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FARM FRIENDS AND 
FARM FOES 

A TEXT-BOOK OF AGRICULTURAL SCIENCE 



BY 
CLARENCE M. WEED, D.Sc. 

STATE NORMAL SCHOOL, LOWELL, MASSACHUSETTS 



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D. C. HEATH & CO., PUBLISHERS 

BOSTON NEW YORK CHICAGO 

1910 



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Copyright, 1910, 
By D. C. Heath & Co. 



©CI.A275540 



PREFACE 

This book is intended to serve as a text and guide for 
the study of those plants and animals so vitally related to 
crop production as often to determine success or failure 
therein. The information given embodies the latest re- 
searches of that host of investigators who have done such 
great service in the advancement of agriculture in recent 
years. The text has been so combined with directions for 
observation and expression that it is hoped that teachers 
will be able to lead their pupils to a first-hand knowledge 
of the most important plants, insects, birds, and mammals 
to be found in the region of the school. 

Most of the original engravings are from drawings by 
Mr. W. I. Beecroft, a few being adapted from the publica- 
tions of authors to whom credit is given in the list of illus- 
trations. Many of the insect pictures are from woodcuts 
originally made for the classic report on Insects Injurious 
to Vegetation, by Dr. T. W. Harris, for the use of which 
thanks are returned to Mr. J. Lewis Ellsworth, Secretary 
of the Massachusetts State Board of Agriculture. For 
courtesies in connection with other illustrations I am in- 
debted to Misses Hazel Dearth, Alice Manning, and I. S. 
Cragin, and Messrs. James Flail, A. I. Randall, E. D. San- 
derson, A. D. Selby, A. H. Verrill, and C. W. Woodworth, 
as well as to the Experiment Stations of Illinois and New 
Hampshire and the United States Department of Agri- 
culture. I have also to thank Mr. W. F. Fiske, of the 
Gypsy Moth Laboratory, for kindly reading the proof of 
the chapters on Predaceous and Parasitic Insects. 

C. M. W. 
iii 



CONTENTS 



PART I 
FRIENDS AND FOES AMONG THE WEEDS 

CHAPTER PAGE 

I. The Weeds of Roadsides and Waste Places . 

II. The Weeds of Meadows and Pastures . 

III. The Weeds of Gardens and Cultivated Fields 

IV. The Weeds of Grain and Forage Crops . 
V. The Economics of Weeds 



i 

13 
3i 

45 
55 



PART II 
FRIENDS AND FOES AMONG THE INSECTS 

VI. ORTHOPTERA : THE GRASSHOPPERS, CRICKETS, AND COCK- 
ROACHES 65 

VII. HEMIPTERA : THE TRUE BUGS 73 

VIII. The Butterflies and Moths 96 

IX. The Two-winged Flies 122 

X. Coleoptera: the Beetles 131 

XI. Hymenoptera : the Ants, Bees, Wasps, and Sawflies . 149 

XII. Insecticides and their Application 155 

XIII. The Predaceous Insects 163 

XIV. The Four-winged Parasites 174 

XV. The Two- winged Parasites 188 

XVI. The Pollination and Fertilization of Flowers . .194 

XVII. The Insect Pollinators 203 

PART III 
FRIENDS AND FOES AMONG THE FUNGI 

XVIII. The Mushrooms, Toadstools, and Molds . . .215 

XIX. The Downy Mildews 219 

XX. The Smut Fungi 226 

XXI. The Rusts 231 

v 



vi CONTENTS 

CHAPTER PAGE 

XXII. The Ascospore and Other Fungi 242 

XXIII. Bacterial Diseases of Plants 229 

XXIV. Preventives of Fungous Diseases 264 

XXV. Fungous Diseases of Insects . . . . . .271 

XXVI. Bacteria and Plant Food 275 

PART IV 
FRIENDS AND FOES AMONG THE BIRDS 

XXVII. The Relations of Birds to Fruit Orchards . . 285 

XXVIII. The Relations of Birds to Meadows and Pastures . 291 

XXIX. The Relations of Birds to Gardens and Fields . 296 

PART V 

FRIENDS AND FOES AMONG THE MAMMALS 

XXX. The Squirrels 3°7 

XXXI. The Mice and Rats 3 12 

XXXII. The Rabbits, Pocket Gophers, Moles, and Shrews . 321 

Bibliography 3 2 & 

Index 329 



LIST OF ILLUSTRATIONS 

PAGE 

Monarch Butterfly. From Nature Biographies ..... xi 

Cover Design for Booklet. From a Japanese Stencil .... 2 

Dandelion Seedheads .......... 5 

Burdock ............ 7 

Broad-leaved Dock .......... 8 

Evening Primrose ........... 10 

Toadflax or Butter-and-Eggs . . . . . . . . .11 

Milkweed Pods 13 

Sprig of Johnson Grass. Redrawn from Cates and Spill man . . 14 

Squirrel-tail Grass ........... 15 

Cone-flower ............ 16 

Canada Thistle ........... 18 

Milkweed Seeds ........... 21 

Sheep Sorrel ............ 22 

Hardhack ............ 24 

Poison Hemlock ........... 26 

Poison Ivy. From Drawing by A. I. Randall ..... 27 

Quack Grass ............ 31 

Pigeon Grass ............ 32 

Shepherd's Purse ........... 33 

White Pigweed 35 

Ragweed 37 

Clotbur 38 

Ground Cherry or Physalis ......... 40 

Jimson Weed ............ 4 1 

Gill-over-the-Ground .......... 44 

Mixture of Weed Seeds. From U. S. Department of Agriculture . 46 

Meadowsweet ........... 55 

Spud 5 6 

Broad-leaved Dock. Redrawn from Henkel . 59 

Goldenrod Seedheads .......... 61 

Cover Design for Booklet on Insects ....... 64 

Mouth Parts of Grasshopper 66 

vii 



viii LIST OF ILLUSTRATIONS 

PAGE 

Grasshopper : Nymph and Adult 66 

Oblong Leaf-winged Grasshopper. From Harris ..... 67 

Common Cricket. Female. From Harris ...... 68 

Tree Crickets : Male and Female. From Harris ..... 68 

Mole Cricket. From Harris 70 

Squash Bug ............ 73 

Chinch Bug. From Harris ......... 75 

Map showing Distribution of Chinch Bugs. After Webster ... 76 
Periodical Cicada ........... 79 

Tree Hoppers. From Harris ........ 80 

Scale Insects on Rose 83 

San Jose Scale ........... 84 

Black Scale 85 

Spring Grain Aphis. Redrawn from Webster ..... 88 

Eggs of Apple Aphis . . . . . . . . . .91 

Ant attending Aphides .......... 92 

Elm Leaf affected by Aphides ........ 93 

Cicada emerging from Nymph Skin. Photograph by A. H. Verrill . 95 
Promethea Moth Cocoon ...... ... 96 

Orange-dog Caterpillars. Photograph by A. H. Verrill. ... 98 

Butterfly of Orange-dog Caterpillar. Photograph by A. H. Verrill . 99 

Luna Moth ............ 102 

Tent Caterpillar ........... 103 

Gypsy Moth 104 

Army Worm 108 

Cutworm Larva. From Harris . . . . . . . .110 

Cotton Bollworm. Photograph by A. H. Verrill . . . . .ill 

Codling Moth 113 

Apples showing Calyx Open and Calyx Closed . . . . .114 

Leaf Roller Moth. From Harris . . . . . . 115 

Peach-twig Borer. After Clarke . . . . . . . . 117 

Tineid Moth 118 

Winter Nest of Brown-tail Moth 121 

Hessian Fly . . . . . . . . . . . .122 

Hessian Fly Magnified 123 

Apple Maggot 125 

Channels of Apple Maggot . . . . . . . . .126 

Cabbage Maggot. Adapted from Washburn . . . . .127 

White Grub or May Beetle . . . . . . . . .131 

Lamellicorn Beetle. From Harris . . „ . . . .132 

Potato injured by White Grub . . . . . . . .132 



LIST OF ILLUSTRATIONS ix 

PAGE 

Rose Chafer. From Harris. ........ 

Eyed Elater. From Harris ......... 

Leaf Beetle. From Harris ......... 

Colorado Potato Beetle 

Flea Beetle 

Round-headed Apple-tree Borer. From Harris ..... 

Plum Curculio ........... 

Strawberry Weevil. Redrawn from Riley ...... 

Peach injured by Curculio ......... 

Mexican Cotton Boll Weevil ......... 

Infested Cotton Square .......... 

Cherry Sawfly ........... 

Willow Sawfly Larva .......... 

Head of Aphis. Redrawn from Slingerland ..... 

Bucket Pump ........... 

A Simple Spraying Outfit. Redrawn from Marlait .... 

Powder Gun ............ 

Tiger Beetles. From Harris ........ 

Ground Beetles. From Harris . . . 

Tiger Beetle Larva. From Harris ....... 

Ladybird Beetle and Pupa. From Harris 

Blister Beetle. Frotn Harris ........ 

Soldier-bug ............ 

Robber Fly. From Harris . . . . 

Syrphus Fly ............ 

White-faced Hornet. From Packard 

Dragon-fly ............ 

Egg Mass of Mantis 

Dragon-fly. From Harris ......... 

Ichneumon Fly ovipositing in Cocoon . . ..... 

Long-tailed Ichneumon Fly. From Harris ...... 

Ichneumon Fly and Chrysalis. Photography by A. H. Verrill 
Ichneumon Flies. From Harris ........ 

Cocoons of Microgaster Flies. From Harris ..... 

Caterpillar with Cocoons of Parasites ....... 

Parasite of Grain Aphis. Redrawn from Washburn .... 

Chalcid Parasite of Gypsy Moth's Eggs. After Howard 

Pelecinus Fly ........... 

Tachinid of Army Worm. Draxvn from Photograph by Slingerland 

Tachinid Parasite of Gypsy Moth. After Fiske 

Cherry Blossoms . . ......... 



x LIST OF ILLUSTRATIONS 

PAGE 

Structure of Cherry Blossom ......... 19c 

Pollination and Fertilization ......... 19c 

Cucumber Flowers. After Drawings by James Hall . . . .196 

Strawberry Blossoms . . . . . . . . . .198 

Pear Blossoms ........... 198 

Leg of Bumblebee ........... 202 

Bumblebee. Photograph by A. H Verrill ...... 205 

Easter Lily ............ 209 

Pear Leaf Blight. Redrawn from Galloway . . . . . .214 

Mushroom . . . . . . . . . . . .215 

Mushroom Spawn. Drawn from Photograph by Atkinson . . .216 
Mycelium of Mold. Redrawn from Zopf . . . . . .217 

A Dying Mushroom . . . . . . . . . .218 

Potato Leaf affected with Late Blight. After Galloway . . . 220 

Spores on Leaf . . . . . . . . . . .221 

Smut Sporidia ........... 226 

Oats Smut ............ 227 

Corn Smut. Drawn from Photograph by Selby ..... 228 

Spore Germinating: seen from Above. Redrawn from R. E. Smith . 232 
Spore Germinating: seen from Side. Redrawn from R. E. Smith . 232 
Black Knot on Wild Cherry ......... 243 

Apple Scab ............ 245 

Apples dwarfed by Scab. Redrawn from Chester ..... 246 

Apples affected by Bitter Rot. From Scott, U. S. Department of Agri- 
culture ............ 247 

Brown Rot Spores Developing ........ 248 

Brown Rot Spores Germinating 248 

Potato Leaf affected by Early Blight. After Galloway .... 255 

Bee's Claw with Blight Bacteria. After Whetzel and Stewart . . 260 
Fly with Fungus ........... 273 

Soy Bean Root showing Tubercles. From Hopkins .... 277 

Red Clover: Effect of Bacteria. Drawn from Photograph by Hopkins . 279 
The White-throated Sparrow. After Biological Survey . . . 284 

Tent Caterpillar Nest attacked by Birds 287 

May Beetle. From Harris . . . . . . . . .291 

Click Beetles. From Harris ........ 292 

Meadow Grasshopper. From Harris ....... 293 

Screech Owl. Photograph from Life ....... 294 

Prairie Dog Burrow : Sectional View. After Merriam . . . 306 

Field or Meadow Mouse. After Samuels . . . . . .312 

Wild Morning-glory Roots. Drawn from Photograph by Lantz . .314 



LIST OF ILLUSTRATIONS 



XI 



Hyacinth Bulbs eaten by Pine Mice. Photograph from Lantz 
White-footed or Deer Mouse. After Samuels 
Cornstalk ruined by Brown Rats. Photograph from Lantz 
Rat Trap used in Burma. After Lantz .... 
Barrel Trap for Rats. After Lantz .... 

Wellhouse Rabbit Trap. After Lantz .... 
Georgia Gopher. After Biological Survey 



315 
318 
319 
3 ! 9 
320 

323 

324 




PART I 

FRIENDS AND FOES AMONG THE 

WEEDS 




Cover Design for a Booklet on Weeds 



The Booklet on Weeds 

Every pupil should make a booklet for each of the important subjects 
taken up for study. The booklet should be composed of such drawings 
and language work as is done in connection with the study as well as 
mounted leaves or other specimens that are readily included in it. 

The ordinary plain paper used for drawings serves very well. A good 
size is six by nine inches. Three holes should be punched near one end for 
binding with raffia in a cover of thicker paper. 

It is very easy to get material for the booklet on weeds. Characteristic 
leaves, branches, and flowers may be pressed and mounted. Young seed- 
lings also may be preserved. 



FARM FRIENDS AND FARM FOES 



chaptp:r i 

The Weeds of Roadsides and Waste Places 

One of the commonest sources of the seeding of culti- 
vated lands is from the weeds that grow in such abun- 
dance along roadsides and on neglected ground. A great 
variety of weedy plants are to be found in these situa- 
tions, and very often the weeds that first infest tillable 
fields come from the seeds of these plants. Consequently 
our study of weeds may well begin with these wayside 
plants. 

When a plant is common and widely distributed, one 
is pretty certain to find that it is splendidly equipped for 
the battle of life. The Dandelion is a good example of 
such a plant. The root is thick and tough and leathery, 
running straight down into the ground with branches 
toward the bottom. It is filled with a milky juice and is 
intensely bitter to the taste. The thickened root enables 
the plant to store up food one season for the sending 
up of blossoms the next. The tough and leathery struc- 
ture enables it to bear trampling by cattle without injury. 
The bitter taste and milky juice protect it from being eaten 
by insects or higher animals. 

The stem between the root and the leaves is so short 
that there is practically none at all. This also saves the 
plant from injury when it is trodden under foot. The 

3 



4 FARM FRIENDS AND FARM FOES 

leaves are spread out in a rosette ; the lower ones are 
the longest ; the margins are deeply cut ; they are bitter 
and filled with a milky juice. The rosette habit, the 
longer lower leaves, and the incised margins all help the 
plant to get the most benefit possible from the sunlight; 
while the bitter taste and milky juice render the leaves 
unfit for animal food. 

The Dandelion flowers are borne on hollow cylindrical 
stalks filled with a similar bitter juice and covered with a 
woolly coating. By means of the hollow cylinder the 
greatest strength is obtained in proportion to the amount 
of material used, while the woolly coating makes the 
ascent of ants and other wingless creatures difficult. 
Several rows of green straplike bracts surround the 
flower head, forming what the botanists call the involucre. 
With the help of these bracts the flowers close at night 
and in rainy weather. This saves the pollen from being 
washed away by the rain, and probably helps the plant 
by preventing radiation of heat. A large number of 
little flowers are crowded together to make up what we 
call the blossom, thus rendering it so conspicuous that it 
is freely visited by bees, which carry the pollen from 
flower to flower and thus bring about cross-pollination. 

When the little ovules have been fertilized by pollen, 
the Dandelion closes up for a time in order to ripen its 
seeds. Then the flower stem lengthens rapidly, generally 
carrying the closed head above the surrounding grass. 
When the seed ripens, the bracts open and the round 
" blowball " appears, ready for the wind to carry the 
seedlike akenes away. 

It is not strange that a plant with these advantages 
should become a weed, crowding out others, and claiming 
all the space and light and moisture wherever a few Dande- 



WEEDS OF ROADSIDES AND WASTE PLACES 



lions become established. To a greater or less extent, 
practically all the other weeds have similar advantages, 
and one of the interesting things about the study of each 
is to find out what these advantages 
are. This will often point the way 
to the best means of checking the 
increase of the plant. 

The Dandelion also illustrates an- 
other general truth, namely, that the 
way in which we think of a plant 
depends upon our point of view. To 
farmers and to the owners of lawns, 
the Dandelion is a weedy pest, fit 
only to be exterminated. To gar- 
deners, it is a profitable crop plant, 
worthy to be carefully cultivated. 
To physicians, it is a storehouse of 
remedies for human ills. To bota- 
nists, it is a species of great interest because of its adapta- 
tions to the conditions of plant life. To artists and poets 
and many other lovers of nature, it is of inestimable value 
in decorating the landscape and lighting up the fields with 
its wonderful disks of gold. 

Sunflower Family 

The Dandelion is a typical example of the great group 
of plants called the Sunflower family, or Composite. The 
principal character of this group is the association of many 
tiny florets in a flower head. A large proportion of our 
weeds belong to this family, the members of which have 
many advantages in the struggle for existence. 

The various adaptations for the dispersal of the seeds are 
among the important advantages of the composite plants. 




Dandelions 



6 FARM FRIENDS AND FARM FOES 

The seedlike fruits of some are furnished with a fringe or 
tuft of hairs that enables them to becarried long distances by 
the wind. The dandelions, thistles, goldenrods, and asters 
are examples of these. Many others are provided with 
some device for becoming attached to animals. Burdocks, 
clotburs and Spanish needles are examples of these. 
Still others have hard nutlike fruits that are able to float 
upon running water. The tall ragweeds and the common 
ragweeds are examples of these. 

It is easy to understand why the roadsides are generally 
infested with many of the composite plants whose seed- 
like fruits or akenes are blown about by the wind. The 
open road furnishes free passage, and the fences along its 
borders catch hosts of them as they fly along. So the 
goldenrods, asters, thistles, and various sorts of wild lettuce 
are familiar roadside weeds. These are mostly native 
species that are willing to live and let live, and thus do not 
entirely overrun the ground as do such imported pests as 
Prickly Lettuce, a roadside weed which has attracted much 
attention during recent years. It apparently was first 
noticed in New England about 1868, and it is now found 
over a large part of the United States, being especially 
abundant in the Middle West. 

Prickly Lettuce, when mature, is from two to six 
feet high, with a straight stalk bearing large stemless 
leaves, the bases of which clasp the main stalk. The 
flowers are borne in an open panicle on the upper end 
of the stalk, each blossom being small, yellow, and 
not very conspicuous. The first flowers appear about 
midsummer, and others continue to develop until au- 
tumn. The leaves and stems have a milky juice which 
is doubtless a protection from insect attack, while the 
numerous prickles over the surface are likewise a pro- 



WEEDS OF ROADSIDES AND WASTE PLACES 



BURDOCK 



tection from the attack of herbivorous animals. Many 
thousand seeds are commonly produced by a single plant, 
and each of these seeds is furnished with a fine pappus, 
so that it may be carried long distances by the wind. 

This is a difficult weed to keep in check. It occupies 
roadsides and waste grounds very quickly, and its seeds 
are blown from such situations to cultivated fields. The 
growing of hoed crops and repeated mow- 
ing of patches where the plant is es- 
tablished — thus preventing seeding — 
are the most advisable measures of pro- 
tection. 

Among the composite plants whose 
seeds are carried by animals, the Bur- 
dock is perhaps the most generally 
known. Its coarse leaves and spiny seed 
heads are to be found in many neglected 
corners. It is a biennial, making a vig- 
orous growth of leaves near the ground 
during the first season, and storing in 
the root a large amount of nourishment for the rapid de- 
velopment of the great flower stalk the second season. 
The tiny florets are crowded together in composite heads, 
having a pinkish color, and surrounded by a mass of bracts 
with recurved spiny tips. As the seeds ripen, these spiny 
burs become brown and easily break away to be carried by 
any animals that may come in contact with them, scattering 
the seed as they journey. The plants vary greatly in height 
according to the richness of the soil in which they grow. 
They are easily pulled up when quite small, but the second 
season they must be repeatedly cut off below the soil sur- 
face to prevent their blossoming, or else killed by pouring 
kerosene or some other suitable liquid upon the crown. 




8 



FARM FRIENDS AND FARM FOES 



Buckwheat and Plantain Families 

The most familiar members of the Buckwheat family are 
the sorrels, docks, and smartweeds. These all have small 
flowers and the triangular akenes characteristic of the 
family. 

Two species of Dock are abundant and widely distrib- 
uted weeds. These are the Curled Dock, Sour Dock, or 
Yellow Dock, and the Bitter Dock or 
Broad-leaved Dock. The former is 
easily distinguished by its comparatively 
narrow curled leaves. The Curled Dock 
is often used for " greens," but the 
Broad-leaved Dock is so bitter that it is 
not used for this purpose. Both of these 
species are likely to be troublesome in 
wet places especially along the roadsides 
and fences, and can be eradicated only 
by extermination of the roots. These 
contain so much stored-up nutriment, 
that if the plants are simply pulled up 
and left upon the surface of the ground, 
the seeds often mature ; consequently 
it is better to burn the plants or at least 
to cut the stalk away from the roots. 

On account of the way in which the Broad-leaved Plantain 
springs up wherever civilized man appears, the American 
Indians used to call it White Man's Foot. It is the most 
abundant representative of the Plantain family, though in 
fields of grain and forage crops the Narrow-leaved Plantain 
is more troublesome. 

The Broad-leaved Plantain is a sturdy, vigorous plant, 
well adapted to crowding out others in the struggle for 




BROAD-LEAVEDW DOCK 



WEEDS OF ROADSIDES AND WASTE PLACES 9 

existence. Its roots are large and fibrous, taking firm hold 
upon the soil ; the main stem is so short as not to appear 
above the ground ; the broad flat leaves are borne on the 
ends of long stems, forming a rosette on the soil surface, 
so that the trampling of animals does not injure them. The 
leaves are not palatable to higher animals and are eaten 
by very few insects. 

In addition to these advantages the small inconspicuous 
flowers are borne closely along the sides of the strong and 
flexible stalks, upon which the seeds rapidly develop. 
The seeds themselves are provided with a mucilaginous 
covering, which when wet adheres to the fur of animals so 
that they are likely to be carried in many directions. 

The Plantain is especially likely to take possession of 
waste corners of the premises, as well as neglected places 
along roadsides. In lawns it is a vexatious pest, requiring 
constant attention to keep it out. The use of a sharp- 
pointed hoe which will cut off the plant below the surface 
is an effective remedy. During wet weather, the smaller 
seedlings may readily be pulled up by hand. 

Weeds of Other Families 

Three common wayside weeds belong to the Evening 
Primrose family — Fireweed or Willow-herb, Evening 
Primrose, and Sundrops. The first named often springs 
up where a fire has left a lot of ashes for the seeds to 
sprout in. It is seldom really troublesome in cultivated 
land, although its winged seeds must be scattered every- 
where. 

The Evening Primrose is one of the most abundant 
roadside plants. It is especially likely to take possession 
of sloping banks and thrives either in open sunlight or in 
partial shade. Under favorable conditions it grows to a 



IO 



FARM FRIENDS AND FARM FOES 



height of several feet and produces in its curious capsules 
vast numbers of the tiny seeds, which may be blown long 
distances by violent winds. It may be suc- 
cessfully kept in check by repeated mowings 
close to the ground. 

The little plant called Sundrops seems like 
the Evening Primrose in miniature. It is 
often abundant along roadsides, and fre- 
quently spreads to adjacent fields, where it is 
especially troublesome in broadcasted grain 
and forage crops. Thorough tillage in corn, 
cabbage, or some other hoed crop is the best 
way to rid a field of it. 

A great variety of other plants are likely 
to appear as more or less noxious weeds along 
roadsides. Familiar examples in many of the 
states are found in Teasel, Elecampane, and 
Butter-and-Eggs. Each of these may occa- 
sionally become troublesome in cultivated fields if left un- 
molested along the roadsides, but they are comparatively 
easy to keep in check by attention at the proper season. 

Some common roadside weeds have escaped from culti- 
vation. The majority of these are likely to be plants 
formerly grown in flower gardens, although most of them 
are now displaced by more attractive flowers. Throughout 
New England, the pinkish blossoms of Bouncing Bet, or 
Soapwort, are likely to be seen along the roadside near 
an abandoned homestead. In early times this plant evi- 
dently was a garden favorite and it remains along the 
roadside, though it seldom becomes really troublesome 
as a weed. 

In a similar way, the curious Cypress Spurge, the Day 
Lily, and the Live-forever are commonly seen along the 




WEEDS OF ROADSIDES AND WASTE PLACES n 



roadsides, to which they have escaped from gardens. 
They are usually present in solid patches, which are to be 
cleared away only by thorough digging of all the roots. 
As a rule these are not likely to go so far afield or prove 
so troublesome as certain of the aromatic herbs that 
were formerly cultivated. Of the latter Yarrow, Tansy, 
and Caraway are commonly most injurious. The seeds 
of these may be scattered by the wind over considerable 
areas. Consequently it is very 
desirable that the small plants 
be destroyed as soon as pos- 
sible. 

Even some of the plants in 
the vegetable garden may at 
times escape from cultivation 
and become troublesome. The 
most notable illustrations of 
this are found in Horse-radish, 
Chicory, and Salsify or Vege- 
table Oyster. The first named 
reproduces only by vegetative 
roots ; but Chicory and Salsify 
produce seeds that scatter in 
all directions, coming up as 
weeds in situations favorable 
to growth. 

Not all of the plants, how- 
ever, which are likely to take 
possession of neglected bits of ground are to be classed 
as wholly noxious. For example the Sweet Clovers are 
among the most abundant occupants of such soil, crowding 
out other plants and developing a thrifty growth of leaves 
and blossoms. The blossoms are a valuable source of 




Toadflax or Butter-and-Eggs 



12 FARM FRIENDS AND FARM FOES 

nectar for honey bees, and the roots of these clovers im- 
prove the condition of the soil by adding to its store of 
nitrogen and organic matter. It is doubtful whether in the 
case of many bits of waste land occupied by these plants 
it is worth while to attempt to exterminate them. When 
they grow along alfalfa or other fields in which they are 
harmful, however, they should of course be destroyed. 

OBSERVATIONS FOR PUPILS 

1. Make a list of twelve common roadside weeds in your locality. 

2. Make drawings of as many of these as you can to use in your 
Booklet on Weeds. For this booklet print an attractive title-page. 
Perhaps the one on p. 29 will help you in doing this. 

3. Press and mount some of the leaves and flowers of the roadside 
weeds to bind up in your booklet. 

4. Make a list with this heading at the top of the page : 

Roadside Weeds I have seen in Neighboring Fields 

5. Find out how the seeds of roadside weeds are scattered. Make 
lists with these headings : 

Seeds scattered by the Wind 
Seeds scattered by Water 
Seeds scattered by Animals 

6. Always watch for new roadside weeds. When one appears, send 
a specimen to your State Experiment Station to learn its name. Here 
is the sort of a letter you should send : 

, Kansas, 

September 21, 191 1. 
Experiment Station, 

Manhattan, Kansas. 
Gentlemen : I am sending you by this mail in a package 
securely packed a plant I found by the roadside near our 
school. We do not know its name and we shall be greatly 
obliged if you will inform me what it is and whether it is 
likely to become a troublesome weed. 
Sincerely yours, 

James A. Smith. 



CHAPTER II 



The Weeds of Meadows and Pastures 



The weeds of meadows and pastures that have been in 
sod for many years are likely to be native species that 
appear to be trying to bring the fields back to the original 
condition of the untilled land. In a for- 
est region, the land will revert to forest ; 
in a plains region, it will revert to plains. 
This is the natural result of neglect on 
the part of the farmer ; nature is claim- 
ing her own. 

The ways in which these fields are 
brought back to the wild condition are 
well worth studying. Go to such a neg- 
lected pasture and notice how shrubs 
and vines spring up along the sides of 
fences, where seeds have been blown 
by winds or left by birds. Notice how 
these spread outward by means of seeds 
and rootstocks. See how the untilled, 
unfertilized sod is "run out," and re- 
placed by mosses or ferns or other weedy growths, and 
how the seeds of Hardhack, Sweet-fern, and other plants 
begin to grow in the moss. Then see how these low bushes 
form a suitable shelter for poplars, birches, and other trees 
to start, and how these in turn may shade the ground for 
the early growth of larger trees. 

In the plains regions the plants will be different, but the 

13 




Milkweed Pods 



14 



FARM FRIENDS AND FARM FOES 



process of encroachment from the neighboring species will 
be much the same. In pastures where the native grasses 
form the chief forage, a frequent cause of weed invasion 
is found in keeping too many animals in the fields. These 
feed so closely that the grasses are killed out, and other 
plants not eaten by the stock take their places. 

On the other hand, many meadows have problems of 
their own. This is most likely to result from a mixture of 
the seeds of some weed with that of the grass, clover, or 
grain, or it may be through the seeds in the fertilizers from 
the barn. Sometimes these may be weeds new to the lo- 
cality, and it is then very important to exterminate them 
before they scatter seed. 

Troublesome Grasses 

A number of grasses more or less valuable for forage 
often prove difficult to eradicate in meadows and pastures 
where they crowd out more valuable sorts. They are 
able to displace other plants because they spread by creep- 
ing underground rootstocks that take complete possession 

of the soil in all directions. One 
of the worst of these is the 
notorious Witch-grass, Quack- 
grass, or Couch-grass. In lo- 
calities where Johnson-grass has 
been introduced for forage, this 
is likely to prove as troublesome. 
Wire-grass or Flat-stemmed 
Blue-grass is another species 
that is likely to take possession 
Sprig of Johnson-grass f light sandy soil. 

All these troublesome grasses are likely to be introduced, 
either with barnyard fertilizers or with grass and grain 




WEEDS OF MEADOWS AND PASTURES 



15 



seeds. In permanent pastures some patches may be kept 
down by salting, thus inducing close feeding by sheep or 
cattle. In some cases, however, the removal of the turf 
or cultivation with a hoed crop becomes necessary. 

Most meadow and pasture weeds are troublesome, be- 
cause they reduce the product of the land, but the Squirrel- 
tail Grass or Tickle-grass is much worse 
than these, because it produces festering 
sores in the mouths of cattle. Consequently 
it not only reduces the grass and hay crop, 
but it renders them of less value for feeding. 
This is a widely distributed annual, easily 
recognized by its glistening, whitish heads 
of barbed awns, each awn an inch or two 
in length. It is especially troublesome in 
Western meadows and alfalfa fields, being 
considered in many regions the most pes- 
tiferous weed. The seeds are carried by the 
wind, though fortunately they are not dis- 
tributed in grass seed. Rotation with an 
annual crop, or the pulling and burning of 
the plants before the heads appear are the 
only effective remedies, and they necessitate 
community action for the best results. If 
one farmer keeps his meadows free and his 
neighbor does not, there is little benefit to 
either. 

In California a closely related annual grass from Europe 
is troublesome in similar ways. It is called Mouse Barley 
or Wild Barley, and is often abundant in sandy pas- 
tures. 




Squirrel- 

Tail 
Grass 



i6 



FARM FRIENDS AND FARM FOES 



Sunflower Family 

Meadows and pastures that have been seeded for a long 
time are liable to become infested by a number of vigorous 
weeds of the great Sunflower or Thistle family {Compositce\ 
some of which prove exceedingly troublesome unless they 
are carefully eradicated on their first appearance. One of 
the most conspicuous of these is the Oxeye 
Daisy or Whiteweed. In many of the New 
England and Middle states whole fields are 
whitened by it in early summer. The 
blossoms are beautiful, but their beauty is 
not likely to be appreciated by the farmer 
who sees them take the place of a good 
crop of hay. The plant is so distinctive 
on account of the character of the blos- 
soms, with their large yellow centers sur- 
rounded by rays of long white petals, that 
it is at once recognized by every one. The 
flowers are borne on stems one to two feet 
high, several of the stems generally devel- 
oping from a single root. 

It is easy to see why the Oxeye Daisy 
is a dangerous intruder in meadow lands. Its period of 
blossoming extends from May to November, so that it is 
able to ripen an enormous number of seeds. These are 
readily scattered and soon develop into little plants that 
are rarely noticed the first season. They blossom quickly 
the second season, and continue as perennials thereafter. 
Each plant spreads out to form new crowns, and thus crowds 
out the surrounding grasses. The fresh leaves, stems, and 
flowers are distasteful to cattle, and very few insects will 
eat any part of the plant. 




Cone-flower 



WEEDS OF MEADOWS AND PASTURES 17 

The careful pulling of these daisies in meadows or pas- 
tures when they first appear and before they have gone to 
seed, will help greatly in keeping them out. In general, 
frequent rotation of crops with good cultivation and fer- 
tilization is useful in preventing the growth of this as well 
as of other weeds. 

The Orange Hawkweed is another dangerous weed of 
this family introduced from Europe. Although the date 
of its appearance on American soil is comparatively recent, 
it has spread over a large part of the country, and in 
many places has already become seriously troublesome. 
It has a dozen or more medium-sized orange-colored 
blossoms borne on the top of a hairy stem, a foot or more 
high. Nearly all the oblong leaves are in a rosette at the 
base of the flower stalk ; they are hairy and about four 
inches long. The plant lives from year to year by means 
of its rootstocks and runners that spread from a single 
root in all directions. 

The Orange Hawkweed is most likely to appear in pas- 
tures or meadow lands, and should be destroyed by a thick 
layer of salt as soon as noticed. When large areas are in- 
fested, the application of salt at the rate of a ton to the 
acre is recommended. 

The spiny leaves, stems, and purple flower heads of the 
common Pasture Thistle are familiar to every one. This 
plant is a biennial. When one of the winged seeds lodges 
in a bit of soil, it develops the first season into a rosette of 
leaves that store up nutriment in the thickened taproot. 
This rosette lives through the winter and the next season 
sends up the spiny flower stalk to develop a new crop 
of seeds. Fortunately the plant spreads only through the 
seeds and is easily destroyed by cutting off below the 
crown. 



i8 



FARM FRIENDS AND FARM FOES 



The Canada Thistle is distinguished from the common 
pasture thistle by its small flower heads. The plant, as a 
whole, is more slender, while its leaves are narrower and 
more deeply cut. The flowers are purple, 
and are followed by seeds bearing a feath- 
ery pappus. The species is regarded as one 
of the most troublesome weeds, largely on 
account of its perennial roots which spread 
in all directions, so that a single plant may 
become a center from which many others 
develop. Because of these roots, also, the 
difficult to eradicate. Thorough 
plowing, repeated mowing, 
seeding down to get a heavy 
sod, and the application of 
kerosene to the roots are 
the remedies most gener- 
ally recommended. 

When tillable land is 
badly infested with Canada 
Thistles the following pro- 
cedure is recommended by 
the Illinois Experiment Station : — 




^ 



i. Cut the thistles when in full bloom (July) as close to 
the ground as possible. 

2. Plow about three inches deep and sow millet or 

Hungarian grass, seeding heavily ; harrow. This 
may follow the preceding at once or after some 
two weeks' delay. 

3. In September plow under the crop, or save it for hay, 

as desired. At all events, plow and seed liberally 
with rye. 



WEEDS OF MEADOWS AND PASTURES 19 

4. Plow under rye in May and seed again with millet, 

or Hungarian grass, or plant to some hoed crop 
(corn) and give the most thorough cultivation, 
with continued destruction of every remaining 
thistle. 

5. Continue the clean cultivation and sharp lookout for 

thistles another year. 

The Cone-flower, the Flea-banes or White-tops and the 
various sorts of Wild Sunflowers are well-known plants 
that are frequently troublesome in meadows and pastures. 
They generally make a tall and vigorous growth that 
shades the grass beneath, and thus prevents its develop- 
ment. When they take possession, tillage and reseeding 
are necessary. 

The Chondrilla, a curious European plant compara- 
tively recently introduced, proves troublesome in pastures 
with light soils. It is a biennial, developing during the 
first season low-lying rosettes of leaves, very similar to 
those of the dandelion. On these the small yellow com- 
posite flowers appear, to develop later into seed fruits, 
which also are strikingly like those of the dandelion. They 
are scattered by the wind, so that when once introduced 
into a new locality the Chondrilla is likely soon to be gen- 
erally distributed. Cultivation and fertilization seem to be 
the best measures to exterminate it. 

Several trouble makers in lowland pastures are those 
weedy composite plants having spiny or hooked fruits that 
become attached to the wool of sheep or the hair of other 
animals. The Spanish Needles, Bur Marigolds, Beggar 
Ticks, and Stick-tights are examples of these. Such plants 
are likely to develop in undrained areas, and proper drain- 
age is generally necessary to check their increase. Along 



20 FARM FRIENDS AND FARM FOES 

the margins of streams frequent mowing through the sea- 
son will prove helpful. 

The Blue and the White Vervains or Wild Verbenas, 
Ironweed, Joe-pye weed, and the various Wild Asters are 
other well-known plants of this family that are likely to be 
abundant in moist places in pastures and meadows. Drain- 
age, tillage, and seeding down are the best ways to be rid 
of them. 

Carrot Family 

The Wild Carrot, which is typical of the great family of 
umbel-bearing plants, is particularly troublesome in pastures 
and meadows. Such fields are often wholly occupied by 
it, rendering the little grass that may develop practically 
worthless. This plant has been troublesome in the Eastern 
states for many years, and has recently been spreading 
through the fertile fields of the Middle West. 

The small white flowers of the Wild Carrot are crowded 
together in flat conspicuous heads, commonly having a 
little purple flower in the middle. These develop into 
curious masses, suggesting miniature birds' nests, rounded 
in outline. The individual " seeds " are really spinose 
akenes which may be distributed by animals or by the wind 
that blows the whole seed head along when it breaks off. 

The Wild Carrot propagates only by means of seeds, so 
that the main point to be attained in suppressing it is the 
prevention of seeding. This may be accomplished by per- 
sistent mowing, which will finally lead to the death of the 
plants. At first, mowing simply causes new flower-bear- 
ing shoots to be sent out. The plants may also be de- 
stroyed by hand pulling, or by cutting them off slightly 
below the soil surface with a spud, hoe, or disk harrow. 
When a grass field is badly infested with this weed, the 



WEEDS OF MEADOWS AND PASTURES 



21 



best way of treating it generally is to plow and plant with 
cultivated crops for a time. 

In the states bordering on the Gulf of Mexico another 
species of Wild Carrot is very troublesome. It is called 
the Small Carrot. It is a biennial, occurring in all sorts 
of situations to which the seeds may be carried by wind or 
animals. 

Other Herbaceous Weeds 

Two members of the Plantain family are often trouble- 
some in meadows and pastures. The Western or Large- 
bracted Plantain ap- 
pears to have been 
originally native to 
the Mississippi Val- 
ley, but has recently 
become very gener- 
ally distributed in 
grass and clover 
seed. It is com- 
monly classed as 
a winter annual, 
though it may also 
develop from seeds 
scattered in spring. 
It differs from the 
other plantains in 
its plume-like flower 
heads, due to a large 
bract projecting 
from beneath each 

tiny floret on the spike. The leaves are short and narrow 
so that the plants do not become conspicuous until the 




Milkweed Seeds 



22 



FARM FRIENDS AND FARM FOES 



flower heads appear. A single plant may produce three 
thousand seeds which are likely to be carried but a short 
distance. Consequently a dense colony will soon be pres- 
ent, crowding out all other vegetation. Pulling the plants, 
frequent mowing, or tillage in a hoed crop seem to be the 
only remedial methods. The sowing of pure grass and 
clover seed is the most important preventive measure. 

The Ribwort, Rib-grass, or Narrow-leaved Plantain is one 
of the most trying pests that infest light soils. It is com- 
monly introduced in clover and grass seed and soon de- 
velops a thickened rootstock that renders it very difficult 
to eradicate. On account of this rootstock it is a peren- 
nial, so that the mere prevention of seeding will not lead 
to extermination ; the roots must be pulled up, cut off 

deeply, or plowed under. 

On barren sandy lands 
in meadows and pastures 
as well as in cultivated 
fields, the Sheep Sorrel or 
Field Sorrel is likely to take 
complete possession of the 
soil. This well-known weed 
is an indication of poor 
farming, and the best way 
to eradicate it is to enrich 
and till the infested areas. 
Its seed is very commonly 
distributed in barnyard fer- 
tilizers, as well as in other 
ways, and the plant is likely 
to appear in any neglected 
spot where the soil is acid. It is so easily eradicated 
by good methods of farming that it need never become 




Sheep Sorrel 



WEEDS OF MEADOWS AND PASTURES 23 

troublesome. Its presence indicates that lime should be 
applied. 

Another group of plants that are likely to run out the 
grass in light soils in dry situations is that of the Five- 
fingers or Cinquefoils of the great Rose family. The Com- 
mon Cinquefoil, the Silvery Cinquefoil, and the Norwegian 
Cinquefoil are the most abundant species. The Barren 
Strawberry is closely associated with these in structure and 
habit of growth, and is often found in the same situations. 
The Cinquefoils have compound leaves composed of five 
leaflets, while the leaves of the Barren Strawberry are com- 
posed of but three leaflets. Like the common Wild Straw- 
berry all these plants occupy increasing areas by send- 
ing out runners just above the surface of the ground, the 
runners starting new plants that take root and in turn 
send out other runners. In this way the soil is soon 
covered with a mat of plants that prevents the growth of 
grasses. 

These low-growing weedy plants often furnish favorable 
conditions of shade and moisture for the starting of larger 
species like the St. Johnsworts and the Goldenrods. There 
are various kinds of each of these, some of which often 
render hilly pastures yellow with their bloom. Along with 
them are likely to occur the white blossoms of the Yarrow 
and the small flower heads of the Wild Asters. 

The presence of most of these weeds in light soils is an 
indication of the need of soil improvement by tillage and 
fertilization. 

Various kinds of Milkweeds, especially the Common 
Milkweed, are likely to prove troublesome in pastures and 
meadows. Such plants send out underground rootstocks 
in all directions ; from these, vigorous new shoots come up 
so that a strong colony is soon spreading outward to shade 



24 



FARM FRIENDS AND FARM FOES 



and destroy the grass. The winged seeds are scattered 
everywhere; consequently it is very desirable to extermi- 
nate wayside plants. 

Several species of Buttercups abound in lowland meadows 
and pastures. When green some of the more abundant of 
these have an acrid taste that leads cattle to pass them by, 
though this bitterness is so lost in drying that the hay is 
not especially injured. 

Ferns out of Place 

In the more northern regions of our land various species 
of ferns often take possession of parts of meadows and 

pastures. They are likely to start 
along a hedge, fence, or the borders 
of the woods, and gradually to ex- 
tend over a greater area. The 
Brake Fern, or Bracken, is one of 
the most abundant of these. It is 
especially liable to overrun com- 
paratively dry land in the open 
sunshine, while most of the other 
ferns are more likely to overrun 
moist or shaded parts of a field. 
The Sensitive Fern, the Cinnamon 
Fern, and the Flowering or Inter- 
rupted Fern are often troublesome 
in undrained spots. All these 
ferns, however, are symptoms of 
lack of drainage or neglect of til- 
lage, and are to be subdued by im- 
proved agricultural methods. Their destruction when they 
have full possession of the soil is a difficult matter, requir- 
ing frequent hoeing and cultivating for several seasons. 



&s 



HARDHACK 



Top View 



CAPSULE 



Side View 



WEEDS OF MEADOWS AND PASTURES 25 

Troublesome Trees and Shrubs 
Over a great central region in the United States the 
Sassafras is a troublesome fence-side bush. Its seeds are 
carried by birds, and its underground rootstocks spread out 
to form a thicket of new plants. In the latter respect, it 
resembles the Yellow or Black Locust, though the seeds 
of this tree are scattered by the wind. When Locust 
thickets are once established in a pasture or meadow, they 
are difficult to eradicate. Their presence, however, is not 
so dangerous as that of the Honey Locust, for the great 
thorns of this tree sometimes penetrate the feet of cattle 
and cause much trouble. 

Many other trees and shrubs are liable to prove trouble- 
some in pastures and meadows if permitted to establish 
themselves along walls and fences. The surest way to 
prevent their spreading is to cut them off as fast as they 
appear, cutting persistently every year, especially in sum- 
mer when the new growth is finished. It is, of course, de- 
sirable to do away with all needless fences. 

Many kinds of shrubs and trees are likely to take posses- 
sion of neglected pastures, especially in hilly regions. 
In northern localities the Gray Birch and the Aspen 
Poplar spring up in great abundance, as do also the Low 
Juniper and the Red Cedar or Savin. The latter are 
especially likely to arise in clumps of Sweet-fern or Hard- 
hack. These are two of the most troublesome pasture 
shrubs. The easiest way to keep a permanent pasture free 
from such intruders is to exterminate them as fast as they 
appear, before they have obtained a firm foothold. 

Poisonous Pasture Weeds 
The most vexatious meadow and pasture weeds are those 
that not only prevent the growth of grasses, but are 



26 



FARM FRIENDS AND FARM FOES 



poisonous to stock when eaten. Several such pests have 
proved very troublesome in the United States, especially 
in the West, although they are by no means restricted to 
any one region. 

The Loco Weeds are the most notorious of the stocky 
poisoning herbs ; they are so-called because the affected 
animals become " locoed," the Spanish word for crazy. 
Several species are known, all belonging to the genus 
Astragalus, of the great family of Legumes or pod-bearing 
plants. Peas, beans, and vetches are familiar examples of 
the legume family. Two species of Loco Weeds are the 
most important: one is called the Woolly Loco Weed; 
the other the Stem less Loco Weed. Both are sometimes 
called Crazy Weed. 

The Woolly Loco Weed is a perennial plant having a 

general resemblance to a Vetch or 
Larkspur. Its leaves and stems 
are covered with silky hairs that 
give it a silvery effect, and its pur- 
ple flowers develop into two-celled 
seed-pods. Leafstalks and flower 
stalks arise from a short central 
stem. The plant belongs origi- 
nally to a wide area in the Great 
Plains region, between Wyoming 
and Texas, though especially 
troublesome in Colorado, Nebraska, 
and Kansas. In Colorado, it was 
so destructive that bounties were 
offered for its destruction. In 
four years nearly $200,000 was 
paid by the state for this purpose. 
The Stemless Loco Weed has a more slender appearance 




Poison Hemlock 



WEEDS OF MEADOWS AND PASTURES 27 

than the Woolly species. Its leaflets are more slender and 
its pods are one-celled. It is distributed over an even 
greater area than the Woolly Loco Weed. 

The Larkspurs are closely related to the Loco Weeds, 
belonging to the same family of Legumes. There are 
many species of these, several of which are known to be 
poisonous to stock. The Dwarf Larkspur, the Purple 
Larkspur, and the Wyoming Larkspur are the most trouble- 
some kinds. They are especially likely to be eaten in early 
spring, when the leaves offer tempting forage to cattle, be- 
fore the better plants are well started. 

Another weed that has been very troublesome in poison- 
ing stock is the Rattlebox or Rattleweed. This is native 
to a great region extending from New Jersey to Kansas 
and Minnesota, occurring especially in low sandy soils. It 
is dangerous to horses and cattle, both in the pastures and 
in hay. In some of the Western states disease in horses 
caused by it is called the Bottom Disease, because only 
stock pasturing on the so-called bottom lands are likely to 
be affected by it. 

A few poisonous weeds commonly occur in wet places in 
meadows and pastures. Thus the well-known Sneezeweed 
with its attractive yellow flowers is poisonous to cattle, sheep, 
and horses. It is abundant along ditches and the borders 
of ponds and streams. The Poison Hemlock or Spotted 
Cowbane, which occurs in similar situations, is even more 
dangerous. Not only are all parts of the plant extremely 
poisonous to man and animals, but water in which the 
roots have been trampled may prove poisonous. The 
roots have an aromatic taste that leads children to eat 
them, sometimes with fatal results. Both these plants 
should be exterminated wherever they occur. 

In the case of all these poisonous weeds the only safety 



28 



FARM FRIENDS AND FARM FOES 



lies in exterminating them to as great an extent as possible. 
And it is especially important that there be cooperation to 
this end among all the landowners of a locality. 



POISON IVY 



Poisonous Trees and Shrubs 

The Choke Cherry is one of the commonest and most 
dangerous of shrubs. It is found along roadsides, woods 
and fences, throughout the greater part of Canada and the 

United States. Its seeds are 
scattered everywhere by birds, 
and it spreads rapidly by un- 
derground stems. As the leaves 
wilt after the bushes are cut, 
Prussic acid, a virulent poison, 
is formed within them by the 
combination of two nonpoison- 
ous substances. This is often 
fatal to cattle that feed upon 
the withering branches. Conse- 
quently it is desirable to prevent the growth of Choke 
Cherry bushes, and to leave no freshly cut leaf-bearing 
branches within the reach of stock. 

Black Cherry leaves also develop this poison as they 
wither, and perhaps the same is true of other wild cherries. 
Certain species of Laurel, especially the Mountain Laurel 
and Sheep Laurel or Lamb-kill, are poisonous to stock. 
The leaves and green stems contain a principle that is even 
more fatal than strychnine. 

Among the more important shrubs that are likely to 
spread from walls and fences into the adjacent fields are 
the various species of Sumachs. The seeds of these are 
left along fences by birds, and the resulting plants, when 




WEEDS OF MEADOWS AND PASTURES 



29 



well grown, send out rootstocks in all directions. From 
these rootstocks other plants arise, so that a continually 
expanding thicket of shrubbery is soon established. The 
Smooth, the Dwarf or Mountain, and the Staghorn or Vel- 
vet Sumachs, are the common nonpoisonous species. The 
Poison Ivy and the Poison Sumach or Poison Dogwood are 
the poisonous species. The Poison Ivy is one of the most 
generally distributed. These, however, are harmful chiefly 
to mankind and are external irritants rather than internal 
poisons. 



A LITTLE BOOK 



OF 



PROFITLESS WEEDS 



BY 



CHARLES R. JONES 



Tough thistle choked the fields and killed the corn, 
And an unthrifty crop of weeds was borne. 

— Dryden. 



ILLUSTRATED 

THE BROWN SCHOOL 
1910 



A Suggestion for Title-page of Booklet on Weeds 



30 FARM FRIENDS AND FARM FOES 

OBSERVATIONS FOR PUPILS 
Pasture Weeds 

i. Make a list of twelve weedy plants that you have seen growing in 
the pastures of your locality. 

2. Are such plants more troublesome along fences, hedges, or walls, 
than in the open pasture ? 

3. Are weeds more abundant in pastures heavily stocked with domes- 
tic animals or those lightly stocked ? 

4. What are the best ways of getting rid of pasture weeds in your 
vicinity ? 

5. If a weedy pasture is near, make a list of the weeds present and 
mention the way in which each kind probably got started in that field. 

6. How often are pastures plowed up and reseeded in your locality ? 

Meadow Weeds 

1. Make a list of the ten most troublesome weeds present in the 
meadows of your locality. 

2. See if you can tell which ones were probably started by being 
mixed with grass, grain, or clover seed; which were blown in by the 
wind ; and which were brought in in other ways. 

3. Are any of these plants that have been recently introduced into 
your region ? 

4. If a meadow is near, make a list of the weeds present and mention 
the way in which each kind probably got started in that field. 

5. How often are meadows plowed up and reseeded in your locality ? 

6. Which meadows show the most weeds, those recently seeded 
down or those that have been seeded down for a long time ? 

Read such references in the following as your teacher directs : — 
Some Poisonous Plants of the Northern Stock Ranges, Farmers' Bulletin 206. 
Thirty Poisonous Plants, Farmers' Bulletin 86. Johnson-grass, Farmers" Bulletin 
279. Canada Thistle, Circular 27, Division of Botany, U. S. Dept. Agr. 



CHAPTER III 



The Weeds of Gardens and Cultivated Fields 

The weeds that infest gardens and cultivated fields are 
familiar to most people. Such plants are seen daily by 
every one in town and country, and must be constantly 
kept in mind by all farmers and gardeners. To a large 
extent they are annuals and produce seed in such abundance 
that neglected soil is quickly covered with young plants. 
Most of them are easily kept in check when the ground is 
given proper tillage. 

Grass Family 

By far the most troublesome of these garden weeds is 
the Quack-grass or Witch-grass, which is known by a dozen 
other names. This notorious pest multiplies both by seeds 
and by underground rootstocks 
that penetrate the soil in all direc- 
tions, sending up leafy branches 
everywhere. If these rootstocks 
are cut into pieces, each piece 
will produce a new plant. On 
this account, hoeing and culti- 

,. -, • r . i T ttt., i OUACK GRASS 

vating ground infested by Witch- 
grass is likely to do more harm than good. When the 
grass has taken complete possession of a piece of land, it is 
often cut for hay, but this only leads to the wider scatter- 
ing of the seeds through the fertilizers from the barn. 

Quack-grass thrives upon ordinary tillage, and is to be 
subdued only by a vigorous and persistent course of treat- 

31 




32 



FARM FRIENDS AND FARM FOES 



ment. It is often said that to kill it, you must dig it out, 
dry it on a rock, burn it, and then be very careful where 
you put the ashes ! In gardens and limited areas, the best 
way is to dig out the rootstocks, when no crop is in the 
ground, with a tined potato digger and cart them away. 

By keeping persistently at the 
roots every spring and fall, the 
land can finally be cleared. Small 
patches may also be smothered by 
covering the surface with boards, 
tarred roofing paper, or something 
similar. 

Several species of annual grasses 
are likely to become troublesome 
in gardens and fields during the 
latter part of the growing season. 
One of these is the curious Fly- 
away-grass or Old-witch-grass, the 
plume-like seed heads of which 
are to be seen every autumn roll- 
ing before the wind, and finally 
lodging along fences. Because of these heads that thus 
fly along the surface of the ground, dropping their seeds 
as they go, this grass is likely to appear even in ground 
that has been kept free from seeding plants. Consequently 
it is desirable that the grass be kept in check wherever 
it appears. 

Two species of Foxtail or Pigeon-grass are universal 
weeds. The Yellow Foxtail or Common Pigeon-grass 
seems to be generally more abundant than the Green Fox- 
tail or Bottle-grass. They are very similar, except for the 
difference in color. Both appear about midsummer in 
gardens, cultivated fields, and waste places, often carpet- 




WEEDS OF GARDENS AND FIELDS 



33 



ing the ground with their spiked heads. When mowed off, 
they send up new heads, which are able to develop close to 
the soil surface. The seeds of the Foxtails are commonly 
distributed in clover and millet seed, and so 
are often sown with these. Persistent late 
culture and hand weeding are the only effi- 
cient means of checking these grasses. 

One or more kinds of Crab-grass or 
Finger-grass are very likely to develop after 
midsummer, especially in wet seasons or on 
moist land. These have the peculiarity of 
spreading their stems in all directions, the 
stems striking roots into the soil whenever 
in close contact with it. This makes the 
plant difficult to eradicate, because any of 
the rooted stems left will continue to grow. 
Fortunately it is an annual and so does not retain posses- 
sion from season to season. It is likely to develop in 
neglected barnyards and thus have the seeds scattered with 
the fertilizers. 

The seeds of the Barnyard Grass are also very likely to 
be scattered in the way just mentioned. This is a tall coarse 
plant, often reaching a height of three or four feet. It 
frequently develops in corn and potato fields late in summer, 
getting its growth after cultivation ceases. It is compara- 
tively easy to subdue by hand pulling. Under the name 
Japanese Millet it has lately been added to the list of de- 
sirable forage plants. 




SHEPHERDS PURSE 



Mustard Family 

Several abundant garden weeds belong to the Mustard 
family. Wild Mustard or Charlock, Black Mustard, Wild 
Radish, and Peppergrass are familiar illustrations. These 



34 FARM FRIENDS AND FARM FOES 

are all found in gardens more or less, though the Mustards 
are more likely to be troublesome to grain and forage 
crops. 

The Shepherd's Purse is one of the garden weeds most 
likely to develop early in the season. It is able to do this 
because it is a winter annual, developing the autumn be- 
fore into a rosette of low-lying leaves. In spring it sends 
up its slender central stalk, along the lower and middle 
parts of which are a few narrow leaves, some having curi- 
ously incised margins, while along the upper part are the 
small white flowers, crowded together toward the top. 
These develop into the purse-shaped seed pods, borne on 
the ends of slender stems. 

This familiar plant is commonly found wherever a few 
inches of waste ground give it an opportunity to grow. 
Tillage late in autumn or early in spring is the best way to 
destroy it. 

Pink Family 

One or more species of Chickweed are so widely distrib- 
uted that they occur in almost every garden. The Smooth 
Chickweed is known by its smooth leaves and stems, and 
its minute white flowers with the green pistils longer than 
the petals. It is a winter annual. The Mouse-ear Chick- 
weed is known by its hairy leaves. Technically there are 
two species known by the latter name ; one of these is a 
perennial. 

These Chickweeds multiply by spreading over the sur- 
face of the soil as well as by seeds which are produced in 
abundance throughout the season. They are comparatively 
easy to keep in check by proper tillage. 

During the latter part of summer, the heart of the care- 
less gardener is often vexed by the rapid growth of the 



WEEDS OF GARDENS AND FIELDS 35 

succulent Purslane or "pusley." Its thick brown stalks 
creep along the ground, spreading rapidly from the root, 
and seriously interfering with crop growth. The leaves, 
as well as the stems, are smooth and thick, while the pale 
yellow flowers borne in the axils of the leaves generally open 
only in the morning, when the sun is shining. The small 
seeds are produced in capsules, the tops of which come off 
when the seeds ripen. It has been estimated that 1,250,000 
seeds are sometimes produced by a single plant. Fortunately 
this Purslane is an annual, requiring only frequent surface 
tillage for its prevention, although when the plants become 
large, it is necessary to remove them to prevent their grow- 
ing again. This is one of those weeds that compel the gar- 
dener to keep a soil mulch through the summer, and thus 
conserve the moisture during the driest season of the year. 

GOOSEFOOT AND AMARANTH FAMILIES 

The plant commonly called Lamb's Quarters, Goosefoot, 
or White Pigweed, is a widespread and troublesome gar- 
den pest. Where it finds room, it be- 
comes a large and vigorous weed, five 
or six feet high and about two feet in 
diameter. Usually it is two or three 
feet high. The leaves are somewhat 
arrow-shaped, with irregular teeth along 
the margins, and rather long, slender ^JJJj^o 
petioles. The narrow clusters of green- 
ish white flowers appear in the axils 
of the leaves, toward the ends of the 
branches. The general color of the plant is pale green, 
with a whitish powder scattered over the flowers and young 
growth, and often over the leaves, also. The small seeds 
are black and shiny when separated from their greenish 




36 FARM FRIENDS AND FARM FOES 

covering. They are developed in great numbers, and 
often produce plants so crowded together in field and gar- 
den that there is no chance for the regular crop to mature. 

This White Pigweed often grows rapidly, and should 
be destroyed by surface tillage. If it gets started in the 
garden, frequent cultivation is the best way to keep it in 
check. 

The common Pigweed is one of the plants most char- 
acteristic of neglected gardens in the latter part of 
summer. The broad, wavy-margined leaves are borne on 
the ends of long petioles that arise from a cylindrical main 
stalk, which in turn grows from a red root. The plant is 
sometimes known as Redroot. It is an annual, developing 
rather late in the season, and consequently is very likely 
to be found in fields of corn and potatoes after cultivation 
ceases. Each plant produces great numbers of small 
seeds, some of which may ripen as early as August. The 
pest is to be attacked by thorough cultivation, or by hand 
pulling in fields where late tillage is impracticable. 

As far as its flowers and seeds are concerned, the 
Tumbleweed is closely related to the Pigweed, both be- 
longing to the Amaranth family ; but in its manner of 
growth it is very different. The Tumbleweed sends out 
numerous branches, that give it a broad expanse, so that 
when the main stalk breaks off near the root, it is able to 
roll and tumble along the ground with every gust of wind, 
scattering its seeds as it goes. It commonly brings up be- 
side a fence or other obstruction, where regular windrows 
of the plants may sometimes be seen. It is easily kept in 
check in gardens and cultivated fields by tillage or hand 
pulling. 



WEEDS OF GARDENS AND FIELDS 



37 




Sunflower Family 

The Ragweed or Roman Wormwood is a pestiferous 
plant found in most situations where weeds may grow late 
in summer. It is nearly always to be seen along paths 
and highways, in fence corners, and along garden borders, 
as well as in cornfields and wheat stubble. It is an an- 
nual, and has a straight central stalk from 
which many spreadingbranches arise. The 
latter bear numerous leaves with deeply 
cut lobes and many small, greenish, incon- 
spicuous flowers. As in the case of the 
Horseweed, to which the Ragweed is 
closely related, the pollen-bearing blossoms 
are borne along the sides of the branches 
near the tips, while the seed-bearing flowers 
are borne along the lower parts of the 
same branches. One reason the Ragweed is so ubiquitous 
is because the young plants are able to develop in hard 
soil where most weeds cannot get a foothold. 

When mowed off an inch or two above the ground, the 
Ragweed is likely to produce new branches from the 
cut main stalk, from which seeds may develop ; conse- 
quently thorough work is necessary in subduing the pest. 
One effective method is to pasture infested fields with 
sheep. 

In the Middle West, the Giant Ragweed or Horseweed 
is one of the most abundant plants. Its luxuriant growth 
is to be found everywhere, but it is especially vigorous and 
troublesome on moist bottom lands. Poorly cultivated or 
untilled parts of such fields are frequently covered with a 
dense growth of this robust annual, the seeds of which 
are carried by water from one valley to another. It often 



38 



FARM FRIENDS AND FARM FOES 



reaches a height of ten or twelve feet, the simple stems 
shooting straight upward and bearing along their ribbed 
sides the large opposite three-lobed leaves with dentate 
margins. The flowers are small and inconspicuous, being 
borne in rows along the ends of the branches. The staminate 
or pollen-bearing blossoms are above the pistillate or seed- 
bearing flowers. The former are much more abundant 
than the latter. Each of the pistillate flowers bears a 
single seed. As the Horseweed is an annual, it may be 
kept in check by thorough cultivation, or in untilled lands 
by repeated mowings. There is often danger, however, 
that during times of floods, bottom lands may be reseeded 
from regions upstream. 

The Clotbur or Cocklebur is another pernicious weed of 
the Sunflower family, which commonly develops late in the 
season in gardens and cultivated fields. This plant is eas- 
ily known on account of the peculiar burs, or seed heads, 
covered with hooked spines. It is a low-growing annual, 
attaining a height of but a foot or two, but 
spreading over quite an area. The prin- 
cipal stalks are tough and woody, and 
bear the broad triangular leaves on the 
ends of long, slender petioles. Two sorts 
of flowers are borne by each plant, stam- 
inate or pollen-bearing, which appear at 
the upper end of the principal stalk, and 
pistillate or seed-bearing, which develop 
lower upon the same stalk. The pollen drops from the 
former upon the latter, or is blown from plant to plant 
by the wind, and thus fertilizes the embryo seeds. 

The bur really consists of a lot of bracts called, when thus 
grown together, the involucre. As the seeds mature the 
bur hardens, the hooked spines becoming stiffer as they 




CLOT BUR 



WEEDS OF GARDENS AND FIELDS 39 

dry out, until finally they are strong enough to cling to the 
hair or fur of any passing animal. 

Fortunately the Cpcklebur spreads and multiplies only 
through its seeds, so that it is comparatively easy to keep 
in check in cultivated fields by means of clean culture con- 
tinued late in the season. 

Potato Family 

The Horse Nettle is a perennial weed native to the 
southeastern region of the United States, whence it has 
gradually spread westward. Its general resemblance in 
leaf, flower, and fruit to the common potato shows its re- 
lation to that plant. The two belong to the same genus 
— Solanum. The rough, prickly plants attain a height 
of from one to two feet, bearing good-sized oak-like downy 
leaves, with long spines projecting from the midrib on 
both the upper and the lower surfaces. The flowers are 
white or purple, and develop into round yellow berries. 
The latter are composed of a pulpy substance in which 
many small seeds are embedded. These seeds are dis- 
tributed by birds. 

Besides the seeds, the plant spreads and reproduces by 
slender rootstocks that penetrate the soil in all directions 
and live from season to season. These make the Horse 
Nettle a difficult pest to subdue. Clean cultivation and the 
eradication or starving out of the rootstocks are the best 
methods. 

Like the Horse Nettle, the Buffalo Bur is a native of 
America, having originally developed upon the plains of 
the far West, where its burs became entangled in the hairy 
fur of the wandering buffaloes. Since the advent of the 
white man, the plant has spread eastward, until now it is 
found in many regions throughout the country. Like the 



4Q 



FARM FRIENDS AND FARM FOES 



Horse Nettle, also, this plant belongs to the same genus as 
the potato, the flowers resembling those of this common 
vegetable in shape, although they are yellow in color. It 
is an extremely spiny plant, more so than the Horse Nettle, 
and its fruit develops into spinose burs, inside which are 
numerous small black seeds. These become attached to 

clothing or the hair of animals, and 
are thus disseminated, although the 
whole plant is sometimes blown 
from place to place, carrying the 
seeds with it. 

The Buffalo Bur may be kept 
down, if seeding is prevented, either 
by mowing or cultivation. 

Nearly a score of species of 
Ground Cherries, of the genus Phys- 
alis, are found in North America. 
All are readily recognized by the 
curious berry-like fruit inclosed in 
the inflated bell-shaped calyx that 
forms a pod-like covering. The 
foliage resembles that of the to- 
mato. One of the most abundant 
sorts is called the Husk Tomato, or Strawberry Tomato, 
and is grown as an edible fruit. 

These Ground Cherries are readily kept in check in a 
well-tilled garden. Most of them are annuals, though at 
least one is a perennial. 




Ground Cherry or 
Physalis 



Weeds of Other Families 

Many years ago, perhaps in the days of Pocahontas, 
a weedy plant appeared in the gardens of Jamestown, 




WEEDS OF GARDENS AND FIELDS 41 

Virginia. It was a very distinctive species with good- 
sized, dark green leaves, large white flowers, and curiously 
spined fruit capsules. It had a decidedly disagreeable 
odor, and was found to be very 
poisonous. So the plant became 
well known, and when it spread 
to the gardens of the surrounding 
region, it was called Jamestown 
Weed, a name that was gradually Mm c °p su,e 
contracted to Jimson Weed, by ^jp JIMS0N WEED 
which it is now generally known. 

It is also called Thorn Apple, Jamestown Lily, Apple of 
Peru, and Mad-apple. Possibly the last name is due to 
the fact that infusions of leaves have been used for the 
cure of hydrophobia. Or it may be due to the fact that 
the plant when eaten produces convulsions and delirium. 

In addition to the white-flowering Jimson weed, there is 
a very similar purple-flowering species. Both are annuals 
from the tropics, and are especially abundant in the South- 
ern states. Nearly every year children are poisoned by 
eating the seeds. These plants should be destroyed wher- 
ever they are seen. 

There are several creeping plants that are troublesome 
as weeds. One of the worst of these is called the Hedge 
Bindweed or Wild Morning Glory. Its rootstock is peren- 
nial, while the stem and leaves die down every autumn. 
Its leaves are somewhat arrow-shaped, and its white or 
purplish flowers bear a general resemblance to those of the 
cultivated Morning Glory. It is especially troublesome on 
low moist land. 

The Wild Morning Glory is propagated both by seeds 
and by the spreading of underground roots. On account 
of these roots it is a difficult weed to eradicate. Hoeing 



42 FARM FRIENDS AND FARM FOES 

and pulling are effective when only a few of the plants 
are present. 

A similar species is Wild Buckwheat or Black Bindweed. 
The stems and blossoms of this plant are smaller than are 
those of the Bindweed, while the flowers, instead of being 
produced singly on stems, are quite small and clustered to- 
gether in racemes. It is called Wild Buckwheat because its 
seeds are quite similar to those of buckwheat. It is an an- 
nual species, and consequently is not very difficult to subdue 
by cultivation. 

A number of the more abundant weeds are likely to de- 
velop in gardens and plowed fields, during the latter part 
of summer. In some cases they are really a benefit, in 
that they enforce surface tillage during the season when a 
soil mulch is most needed. In fields of corn, potatoes, and 
some other crops, however, such late tillage is impracti- 
cable, and about the only way to fight the weeds is to pull 
them up by hand. 

OBSERVATIONS FOR PUPILS 

i. How many of the weeds treated of in this chapter infest gardens 
and cultivated fields in your locality ? Here is the list : — 



Barnyard Grass 


Hedge Bindweed 


Black Bindweed 


Horse Nettle 


Buffalo Bur 


Jimson Weed 


Chickweed 


Lamb's- quarters 


Crab-grass 


Pigweed 


Finger-grass 


Purslane 


Fly-away-grass 


Ouack-grass 


Giant Ragweed 


Ragweed 


Green Foxtail 


Shepherd's Purse 


Ground Cherry 


Tumbleweed 


YeJlo 


w Foxtail 


2. What other weeds occur in 


gardens and cultivated fields in your 


locality ? 





WEEDS OF GARDENS AND FIELDS 43 

3. Make a list of the field and garden weeds you are acquainted with, 
and print the names in alphabetical order on a page of your booklet. 

4. Make a careful study of such of these weeds as your teacher thinks 
desirable, incorporating the results into your booklet. The following 
outlines may prove helpful for such studies : — 



Purslane 

1. Cofnt the number of seeds in one "pusley" capsule. 

?.. Count the number of capsules on one long branch. 

3. Estimate the number of seeds produced by the plant. 

4. Count the number of plants in a space two feet square, and estimate 

the number of seeds produced in a square rod. 

5. How are " pusley " seeds distributed ? 

6. When do you find Purslane most abundant ? 

7. Make a drawing of stem, leaf, and fruit. 

Lamb's Quarters or White Pigweed 

1. Why should this be called White Pigweed ? 

2. Where have you found it most abundant ? 

3. How are the seeds scattered ? 

4. Do you know how it looks when young ? 

5. Have you seen any leaves affected by leaf miners ? If so, rear some 

of the adult flies from them, and see whether they resemble the flies 
you can easily rear from spinach. 

6. How early should the plants be destroyed to prevent their maturing 

seed? 

7. Draw a good-sized leaf, showing petiole, veins, and margin. 

Outline for Other Weeds 

1 . What sort of root has this plant ? 

2. Does it spread by underground rootstocks ? 

3. How is it protected from being eaten by animals ? 

4. When do the flowers appear ? Describe them. 

5. When do the seeds ripen ? How are they scattered ? 

6. Estimate the number of seeds on one plant. 

7. What do the young seedlings look like ? When may they be found ? 



44 



FARM FRIENDS AND FARM FOES 



8. In what condition does the plant pass the winter— in the seed 

state, or as a living plant, or both ? 

9. How is it commonly introduced to new fields ? 

10. In what ways may it be destroyed or prevented from growing ? 

1 1 . Make some or all of these drawings : — 



Root 
Leaf 



Flower 
Seed 




Gill-over-the-Ground 



CHAPTER IV 
The Weeds of Grain and Forage Crops 

The weeds that infest fields of grain and forage crops 
are commonly introduced with the seed. In many cases, 
however, the weed roots or seeds may be present in the 
soil because of neglect of crops previously grown upon the 
land, or the seeds may be scattered through the fields during 
autumn, winter, and spring before the grain or forage crop 
is sown. Consequently the surest way to prevent injury in 
such fields is to sow clean seed and adopt good agricultural 
methods. 

Grass Family 

Perhaps the most notorious grain-field plant is Chess or 
Cheat Grass. In earlier days there was much discussion 
in regard to the origin of this pernicious plant. The idea 
was very commonly upheld that wheat turned to Chess, so 
that under certain conditions, as it was supposed, a farmer 
might sow good wheat seed and reap only a crop of Chess. 
It seems likely that this was the basis for the use of the 
common name Cheat. It has long been known, however, 
that Chess comes from seed of its own, and not from wheat, 
so that when the Chess appears it is certain, either that its 
seed was present in the ground before sowing or that it 
was mixed in with fertilizers or the wheat that was used 
for seeding. It is well established that the seed of Chess 
may lie dormant in the soil for several seasons, and this 

45 



46 



FARM FRIENDS AND FARM FOES 



probably is the explanation of its presence in many grain 
fields, in which no Chess seed developed the previous 
season. 

Chess is a winter annual, and its slender seeds are some- 
what similar to oats, although they are darker in color, and 
the grain is of smaller size. These seeds are likely to be 
found in cheap qualities of clover, oats, and wheat seed, 




Mixture of weed seeds commonly found in low-grade alsike clover seed: a, alsike 
clover; b, white clover; c, red clover; d, yellow trefoil; e, Canada thistle; 
/, dock ; g, sorrel ; h, buckhorn ; /', rat-tail plantain; k, lamb's-qnarteis ; /, shep- 
herd's purse ; Di, mayweed; n, scentless camomile ; o, white campion ; p, night- 
flowering catch-fly; q, oxeye daisy; r, small-fruited false flax; s, cinquefoil ; 
/, two kinds of peppergrass; u, catnip; v, timothy; x, chickweed; y, Canada 
bluegrass; z, clover dodder ; /, mouse-ear chickweed; 2, knot-grass; j, tum- 
bling amaranth ; 4, rough amaranth ; 5, heal-all ; 6, lady's thumb. (Enlarged.) 



although, as in the case of many other pernicious plants, 
the public inspection of seeds is driving these poorer qual- 
ities out of the market. When a field is infested with 
Chess, it may well be planted to a hoed crop for two or 
three seasons. This procedure, and the sowing of pure 
seed, will prove an adequate preventive. 



WEEDS OF GRAIN AND FORAGE CROPS 47 

In the great spring wheat regions of the Northwest, the 
Wild Oat is one of the most troublesome weeds in fields of 
oats. This plant bears a striking resemblance to the or- 
dinary cultivated oats, from which it is easily known by the 
long-tipped awns borne by the terminal florets of each 
cluster of flowers, and by the fact that the kernel or grain 
is very light. When present in an oats field, these Wild 
Oats mature earlier than the main crop and in an irregular 
fashion, many of the individual florets dropping away as 
they ripen. The presence of the plant not only reduces 
the regular crop, but also sometimes causes trouble because 
the stiff awns irritate the mouth parts of the animals to 
which the crop is fed. 

The seeds of Wild Oats retain their vitality for a long 
period when buried deeply in the soil. Consequently, a 
badly infested field may require several seasons' tillage in 
other crops before all the seeds present have germinated. 
A carefully planned rotation is the best method of getting 
rid of the plant. 

Mustard Family 

In many localities, the most vexatious weeds in grain 
fields are those belonging to the Mustard family. The 
seeds of these are very commonly mixed with oats and other 
grains, so they are sown at seeding time. One of the most 
generally troublesome is the Charlock, Wild Mustard, or 
English Mustard, as it is sometimes called. This was origi- 
nally a native of Europe, but is now very generally dis- 
tributed in America. It is especially troublesome in fields 
of oats, the young mustard plants growing along with the 
oats and materially lessening the crop. Charlock is dis- 
tinguished from the other Mustards by a pod, long and 
knotted, and having at the tip a rather thick, two-edged beak. 



48 FARM FRIENDS AND FARM FOES 

The Black Mustard is a much more prickly plant, having 
pods that are more or less oblong, smooth, and four-angled. 
A single plant of either of these Mustards may produce 
from 10,000 to 1 5,000 seeds. This accounts for the enormous 
numbers of them that often appear in neglected fields. 

In many parts of Canada and the United States, the 
Tumbling Mustard or Tall Mustard has recently become 
a troublesome pest. This species seems to have been in- 
troduced with the soil carried as ballast by ships, and dumped 
on the so-called ballast grounds at Philadelphia. It has 
since been widely distributed by railroads, and is able to 
develop under a great variety of climatic conditions. Like 
the other Mustards, this is an annual. It branches freely, 
and reaches a height of from two to four feet. The small 
yellowish flowers are borne along the tips of the slender 
branches, and are less conspicuous than those of the Char- 
lock. The seed pods are very slender, and are commonly 
two or three inches long. This species is closely related to 
the more widely distributed Hedge Mustard, the pod of 
which is much shorter and of larger diameter. 

In the case of all these Mustards, as with most annual 
weeds, careful cultivation with a hoed crop for a series of 
years is necessary for complete extermination in a field. The 
seeds of many of the plants of the Mustard family retain 
their vitality for several years, so that those which are 
buried deep in plowing, are likely to be brought to the 
surface long after they matured, and find favorable condi- 
tions for growth. It is especially important that grain 
used for sowing be free from the seeds of any of these 
plants. 

Numerous experiments have shown that young mustard 
plants may be killed in grain fields without serious injury 
to the grain crop by spraying with a solution of one part 



WEEDS OF GRAIN AND FORAGE CROPS 49 

iron sulphate to four parts water by weight. The applica- 
tion should be made on a fair day after the dew has evapo- 
rated. 

Another member of the Mustard family, which is 
troublesome in fields of winter grain, as well as in those of 
flax, is the so-called False Flax. This is a pest from 
Europe which has been introduced into America compara- 
tively recently. Its resemblance to Flax is indicated by its 
common name. The flowers and seeds, however, are much 
smaller than those of Flax. In appearance and habit of 
growth, it also bears a general resemblance to Shepherd's 
Purse and Peppergrass. Like these weeds, it may be 
either an annual or a winter annual; that is, the seeds may 
germinate in spring and blossom the same season, or they 
may germinate in autumn, the plants living through the 
winter and blossoming the next season. As a rule, it is 
only the latter that mature their seeds, the season in the 
Northern states being too short for the seeds of those 
plants that germinate in spring to reach maturity. 

False Flax is generally introduced as a mixture in flax 
seed, clover seed, and various grass seeds ; consequently all 
such seeds should be carefully examined before being sown. 
When the pest has become established, rotation with a hoed 
crop is necessary to exterminate it. 

Weeds of Other Families 

The Cockle or Corn Cockle is a well-known pest in grain 
fields. Its presence is generally due to impure seed, the 
black seeds of the Cockle being sown with the wheat or 
other grain. It is an annual, so that it causes little trouble 
unless sown with the seed. It grows to a height of three 
or four feet, and has a slender stem with very few branches, 
each of which bears on its tip a good-sized reddish-purple 



50 FARM FRIENDS AND FARM FOES 

blossom. There are comparatively few of the long, narrow 
leaves, which, with the stem and outer part of the flowers, 
are covered with a coat of fine hairs. 

The dark purple or blackish seeds are produced in an ob- 
long pod. They are threshed with the wheat ; and as they 
are nearly the size and weight of the wheat kernel, it is 
very difficult to separate the Corn Cockle seeds from the 
grain. In consequence the flour is of inferior quality. The 
presence of the seeds is shown by the black particles of the 
pulverized seed coat. Flour badly contaminated by Cockle 
seeds is injurious when eaten, as they contain a poisonous 
principle that produces disease and death. 

The Cockle plants are easily pulled up in wheat fields 
and should be removed, especially from all fields that are 
intended to produce seed grain. 

Few weedy plants have such distinctive beauty as has 
the famous Field Poppy or Corn Poppy of the English 
poets. In England the fields of wheat are called corn 
fields, although in America this term is usually restricted 
to Indian Corn. The Field Poppy has long been a pest in 
European wheat fields ; but it gives to the landscape a 
glow of scarlet color, much as our own meadows are 
decorated with the Oxeye Daisy. This Field Poppy has 
been introduced into many regions in America, probably 
through adulterated seed, and threatens to become trouble- 
some wherever it appears. It is so conspicuous a plant 
that it can scarcely be overlooked, and when first introduced 
into a locality it should be exterminated. This is also one of 
the garden Poppies and of course there is danger that it 
may spread to cultivated fields. 

The famous Russian Thistle or Russian Tumbleweed is 
another European plant that has become destructive in 
America. The history of the introduction of this pest has 



WEEDS OF GRAIN AND FORAGE CROPS 51 

been carefully traced. Apparently it was first brought in 
by immigrants from Russia in the great Northwest, about 
1873, and since then it has spread with marvelous rapidity, 
not only by being blown across long stretches of prairie, 
but also . by means of railroad trains, and probably in 
other ways. It has attracted more attention than any 
other weedy plant of recent introduction, and has been 
the cause of a great awakening in regard to the whole 
subject. 

The Russian Tumbleweed is an annual that starts as a 
slender seedling bearing a general resemblance to a very 
young pine tree. Its leaves are slender, soft, and velvety. 
It grows rapidly, however, and toward midsummer takes 
on a spiny appearance, spreading out to cover an area three 
or four feet in diameter, with the height nearly as great, 
and a rounded outline similar to that of our common 
Tumbleweeds. When the seeds are finally mature and 
ready to be dispersed, the main stalk breaks off at the 
surface of the ground and the plant rolls away. It then 
justifies its German name "Wind Witch," or its Russian 
name " Leap the Fields." With the impetus given 
by a violent wind, the plants go rolling and tumbling 
across the prairies, to be caught in great windrows when an 
obstacle interferes. As they roll along they drop their 
seeds by the way, so that the country traversed is likely to 
become thoroughly infested. 

While the greater part of the weeds that infest grain 
fields arise from seeds present or introduced, it sometimes 
happens that when meadow or pasture land is broken up 
and planted to grain, there is trouble from perennial weeds 
whose roots or rootstocks remain in the soil. Thus, if a 
meadow is infested with milkweeds and is planted to oats, 
the milkweeds will multiply rapidly under the favorable 



52 FARM FRIENDS AND FARM FOES 

conditions for their growth. In such cases rotation with a 
hoed crop is desirable. 

The Parasitic Dodder 

All the weeds so far discussed in this chapter injure the 
crop by robbing the soil of food and moisture, or by oc- 
cupying the space above the soil to the exclusion of the 
cultivated plants. There is one group of pernicious weeds, 
however, which do more than this, for they actually attack 
the green tissues of the crop and rob them of the life- 
giving sap. These plants are commonly called Dodders, 
and there are several species that attack different crops. 
In their life history, however, they are very similar to one 
another. 

The young Dodder plant starts from a seed well stocked 
with nourishment. When the seed germinates, this nour- 
ishment enables it to develop into a seedling which soon 
comes in contact with the stalk of some green plant. 
Then the little Dodder sends out from along the sides of 
its own stalk curious rootlike projections that penetrate the 
tissues of the other plant and draw out the sap. There is 
thus established the relation of parasite and host : the 
parasite is the Dodder sucking the life sap from its victim, 
which is the host plant. The root and lower stem of 
the Dodder soon wither. In the case of clover, which is 
often infested by Dodder, the clover plant continues to 
grow, having roots in the ground and leaves in the air, 
but those clover stalks which are attacked by the Dodder 
become dwarfed as well as hard and woody. 

As the Dodder grows, it constantly twines around more 
stalks of its host plant, sending into their tissues more of 
the rootlike suckers, and after a time developing small 
blossoms which later mature into seed. As the Dodder is 



WEEDS OF GRAIN AND FORAGE CROPS 53 

a parasite, it has none of the green coloring matter of 
most plants, for it is not able to manufacture starch and 
other organic material from the inorganic substances in 
earth and air. Instead of this, it utilizes for its growth the 
materials thus organized by the green leaves of its host. 
The Dodders are commonly yellow or orange in color. 
They have no leaves. 

The seeds of Dodder are a common impurity in many 
grain, grass, and forage seeds. Such seeds should, of 
course, be carefully inspected before planting, and if seri- 
ously infected should not be used. When a field is al- 
ready infested, the Dodder may be destroyed by mowing 
and removing the crop before the Dodder blossoms, or 
later the crop may be mowed and the ground burned over 
after the crop thus cut has dried sufficiently to burn. In 
Western alfalfa fields Dodder is often troublesome the 
first year after seeding, though less so in later years. 

Preventive Measures 

Any study of the weeds that infest grain and forage 
crops makes it obvious that the most important methods 
of preventing injury by such pests are: first, the sowing 
of clean seed, that is, grain free from the seeds of weedy 
plants ; second, the use of fertilizers free from weed seeds; 
and third, a proper rotation with other crops. To insure 
pure seed, constant inspection by state and government 
officials of all seeds offered for sale is necessary. To in- 
sure fertilizers free from weed seeds, care in feeding do- 
mestic animals is necessary. To insure proper rotation of 
crops, the adoption of improved agricultural methods in 
every community is necessary. With these conditions 
right there need be little trouble from weedy plants in any 
locality. There is always danger, however, that some new 



54 FARM FRIENDS AND FARM FOES 

pest will be introduced, and it is very desirable that the 
people of each community should be on the alert for such 
newly introduced weeds. In order that they may do this, 
each school should have a collection of weeds and their 
seeds for reference, and a study should be made of the 
weedy plants of the locality. Any unknown plants may 
be sent to the State Experiment Station, or to the Depart- 
ment of Agriculture at Washington for determination. 

OBSERVATIONS FOR PUPILS 

1. What weeds have you observed in connection with such of the 
following crops as are largely grown in your locality : — 

Alfalfa 

Alsike Clover 

Oats 

Red Clover 

Wheat 

2. Is there any evidence to show that part of these were introduced 
with seed? 

3. Examine with a lens samples of forage plant seeds for sale in your 
locality. Compare the seeds with the pictures in Farmers 1 Bulletin 382. 

4. Determine the percentage of adulteration of the crop seed with 
other seeds. 

5. If you are unable to determine what seeds are present as adul- 
terants, send samples to your State Experiment Station or to the Seed 
Laboratory, Department of Agriculture, Washington, D.C. 

Read such references in these publications as your teacher directs : — 

Dodder in Relation to Farm Seeds, Farmers' Bulletin 306. The Adulteration 
of Forage-plant Seeds, Farmers' Bulletin 382. 



CHAPTER V 



The Economics of Weeds 



Every farmer realizes that weeds are among the most 
important factors in success or failure in agriculture. 
They occur wherever the soil is cultivated and stand ever 
ready to take the place of the crop planted if proper tillage 
is not given. They not only rob the crop of sunshine and 
needed space in earth and air, but they 
also deprive the soil of more or less of its 
available plant food, draw out its mois- 
ture, and according to the present belief 
of some authorities actually poison the 
soil for other plants. 

Weeds, however, are by no means to 
be considered an unmixed evil. In many 
cases they are rather to be thought of as 
a blessing in disguise, for they compel 
that tillage of the land which is neces- 
sary for the conservation of moisture and 
the healthy growth of most crops. " The 
truth is," writes L. H. Bailey in a famous « 
paragraph, " that weeds always have 
been and still are the closest friends and helpmates of the 
farmer. It was they which first taught the lesson of the 
tillage of the soil, and it is they which never allow the les- 
son, now that it has been partly learned, to be forgotten. 
The one only and sovereign remedy for them is the very 

55 




Meadowsweet 



56 



FARM FRIENDS AND FARM FOES 



tillage which they have introduced. When their mission is 
finally matured, therefore, they will disappear, because 
there will be no place in which they can grow. It would 
be a great calamity if they were now to disappear from 
the earth, for the greater number of farmers still need the 
discipline which they enforce. Probably not one farmer in 
ten would till his lands well if it were not for these pains- 
taking schoolmasters, and many of them would not till at 
all. Until farmers till for tillage's sake, and not to kill the 
weeds, it is necessary that the weeds shall exist, but when 
farmers do till for tillage's sake, then weeds will disappear 
with no effort of ours." 

While the beneficence of weeds as a whole must be ad- 
mitted as a fortunate fact, it is also true that often they 
are not even a blessing in disguise. Like other things 
in Nature, the laws that govern them involve many in- 
conveniences in special cases. Rain is a blessing, 
but sometimes it causes suffering and loss of prop- 
erty and even of life. Winds are necessary, but 
often do serious harm by their violence. With 
weeds, as with these direct forces of Nature, man 
must adapt his operations to suit the conditions 
that he finds upon his land in his efforts to make 
it productive. 

Examples of weeds that could easily be dis- 
ij pensed with are readily pointed out. The Mus- 
tard in a newly planted grain field does not indi- 
cate that tillage is needed, although it does in- 
dicate that there has been carelessness in seed 
selection. During rainy seasons the hoe and cultivator 
must frequently be kept in operation to subdue weeds 
much oftener than any requirements of the crop alone 
would necessitate. The weeds that appear late in the 



GPUO 



ECONOMICS OF WEEDS 57 

season in corn and potato fields require hand pulling 
because tillage then would injure the crops, and often 
even hand pulling involves some loss through the disturb- 
ance of the roots. 

The most famous definition of a weed is that it is a plant 
out of place. In soil devoted to a crop of a given kind, 
the presence even of other crop plants is generally not 
wanted. So under some circumstances our ordinary grains, 
vegetables, and flowers may appear as weeds. In fact, in 
the case of the flowers many weeds have originated as gar- 
den escapes, and there is always danger that new ones may 
be so introduced. 

The Struggle for Life 

It is well known that the most troublesome weeds are 
those best equipped in the struggle for life. By being 
able to grow quickly where other plants grow slowly, by 
producing many seeds where other plants produce few 
seeds, or by being able to do anything else that enables it 
to get on in the world better than its neighbors a plant 
has an advantage that tends to make it a weed. There is 
always an intense struggle for soil, moisture, air, and sun- 
light, and the plants best fitted to take advantage of con- 
ditions existing at a given time and place will win. It is 
the farmer's business so to plan his operations that the 
crops he sows will have the advantage of all weedy in- 
truders. 

One of the chief advantages that most weeds have in 
the struggle for life lies in the production of great num- 
bers of seeds. This is well shown in the following esti- 
mates by the Kansas Experiment Station of the number of 
seeds ripened by one plant, made after careful studies of 
each species : — 



58 



FARM FRIENDS AND FARM FOES 



Name of Weed 
Purslane 
Velvet leaf . 
Ragweed 
Cocklebur . 
Beggar-ticks 
Redroot 
Tumbleweed 
Crab-grass . 
Yellow Foxtail 



Number of Seeds 
69,000 
31,900 
23,100 
9,700 
10,500 
85,000 
14,000 
89,600 
113,600 



When plants are able to multiply at this rate, it is easy 
to see how readily they might overrun the earth. 



Methods of Distribution 

Under the conditions of Nature weeds are dispersed in 
almost all the many ways in which plants spread. They 
are carried by wind, water, and animals, and exhibit number- 
less devices for taking advantage of these agencies. The 
study of these devices is of great interest. 

Under the conditions of modern agriculture, however, 
man plays an important part in the distribution of weeds. 
Vast numbers of seeds are carried from place to place in 
hay, ballast, and packing materials, and even more are dis- 
persed as impurities of grains and commercial seeds. 

During recent years enormous numbers of weed seeds 
have also been distributed in the various stock feeds upon 
the market. Many investigations have shown that a large 
part of these seeds are not digested, so that when they reach 
the fields from the barn they germinate quickly. As a rule 
these seeds are not readily detected in the feed because 
they are mingled with chaff and grain or smeared over with 
molasses. By careful studies, however, experiment station 
officials have been able to identify and count these seeds 
and to show the danger in the use of such feeds. 



ECONOMICS OF WEEDS 



59 



The Connecticut Experiment Station has shown that in 
the case of eleven feeds upon the market, there were the 
following numbers of weed seeds in one pound of each : — 



No. 


i 


No. 


2 


No. 


3 


No. 


4 


No. 


5 


No. 


6 



11,528 

7,800 

. . . . . 29,324 

22,224 

8,574 

6 27,100 



No. 7 8,160 

No. 8 10.360 

No. 9 48,663 

No. 10 21,267 

No. 11 86,000 



SMS 




The seeds thus present in such enormous numbers be- 
longed to a comparatively few species of the most trouble- 
some weeds. Among the most abundant of these were the 
foxtail grasses, white pig- 
weeds, knot-weeds, char- 
lock, black mustard, rag- 
weed, sorrel, docks, and 
thistles. "All of these 
weeds are characteristic of 
grain screenings which are 
the refuse separated from 
the grain, in order to make 
the latter marketable or fit 
for milling. These screen- 
ings vary a good deal in quality. Thus an analysis recently 
made here of wheat screenings showed about 33 per cent 
of flax and shrunken cereal, 15 per cent of foxtails, 8 per 
cent of bindweeds and pigweeds, 15 per cent of weed seeds 
of other species, and 21 per cent of dust, broken seeds, 
and sand." 

Length of Life 

One of the most important considerations in regard 
to any weed is its length of life. If it lives but one 



Broad-leaved Dock 
Growth of First Season 



60 FARM FRIENDS AND FARM FOES 

season, it is likely to be less dangerous than if it lives 
two or more seasons. Like other plants, weeds are com- 
monly grouped as annuals, living but one year, biennials, 
living two years, and perennials, living many years. The 
phrase winter annuals is given to those plants that start 
their growth in autumn and finish their development the 
following spring or summer. 

The remedial measures to be taken against weeds depend 
largely upon the term of life. The annuals live from year 
to year by means of their seeds. Consequently the preven- 
tion of seeding by tillage or other means and the destruction 
of the seed are the most important general measures. It 
has lately been found that some annuals like the mustards 
may safely be killed in grain fields by spraying with a weak 
solution of iron sulphate. The biennials reproduce also 
by seeds, and are to be treated much as the annuals. The 
perennials commonly reproduce both by seeds and by root- 
stocks or other vegetative growths, so that their destruction 
is generally more difficult than in the case of the annuals 
and biennials. 

The methods that may be employed for the destruction 
of the roots or rootstocks of perennial weeds have been 
well summarized by L. H. Dewey in these words : — 

( i ) They may be dug up and removed, a remedy that can 
be practically applied only in small areas. 

(2) They may be killed by applying chemicals either to 
the freshly cut root or at the base of the main stem. Salt, 
strong brine, coal oil, crude sulphuric acid, and carbolic 
acid have been successfully used for this purpose. A few 
drops of carbolic acid applied at the base of the main stem 
with an ordinary machine-oil can is the best method that 
has been yet devised for killing weeds with chemicals (ex- 
cept spraying with sulphate of iron). 



ECONOMICS OF WEEDS 



61 



(3) Rootstocks or perennial roots may be starved to 
death by preventing any development of green leaves or 
other parts above ground. This may be effected by build- 
ing straw stacks over small patches, by persistent, thorough 
cultivation in fields, by the use of the hoe or spud in waste 
places, and by salting the plants and turning sheep on in 
permanent pastures. 

(4) The plants may usually be 
smothered by dense sod-forming 
grasses or by a crop like clover or 
millet that will exclude the lie-ht. 

( 5 ) Most rootstocks are readily 
destroyed by exposing them to 
the direct action of the sun dur- 
ing the summer drought, or to the 
direct action of the frost in the 
winter. In this way plowing, for 
example, becomes effective. 

(6) Any cultivation that merely 
breaks up the rootstocks and 
leaves them in the ground, especially during wet weather, 
only multiplies the plant and is worse than useless, unless 
the cultivation is continued so as to prevent the growth 
above ground. Plowing and fitting corn ground in April 
and May, and cultivating at intervals until the last of June, 
then leaving the land uncultivated during the remainder of 
the season, is one of the best methods that could be pur- 
sued to encourage the growth of couch-grass and many 
other perennial weeds. 

Recent studies by Spillman and Cates have shown that 
the rootstock grasses, like quack grass, Bermuda grass, and 
Johnson grass, are readily killed out by allowing the fields 
to become meadows and pastures, so that a dense sod will 




GOLDENROI) SEEDHEADS 



62 



FARM FRIENDS AND FARM FOES 



form. Then cut or feed off the grass frequently to induce 
a shallow development of rootstocks. These may then be 
turned up by shallow plowing and destroyed by clean cul- 
ture, summer fallowing, or winter freezing. 

Lessons from Weeds 

The most important general lessons we may learn from 
our study of weeds are, first, that good agriculture is the best 
preventive of their injuries, and, second, that this must be 
practiced not only by all the farmers of a given community, 
but by all farmers everywhere. So it becomes the duty 
of each one to adopt the best methods practicable on his 
own farm as well as to encourage in every way possible 
the practice of such methods in every locality. 




Hardhack 



OBSERVATIONS FOR PUPILS 

Choose certain weeds which you have not before 
reported upon and see if you can answer these ques- 
tions about each : — 

i. Where did it come from ? 

2. How does it spread ? 

3. How long does it live ? 

4. How does it pass the winter ? 

5. How does it injure the crop ? 

6. Is it poisonous or hurtful to domestic animals ? 

7. In what ways may it be destroyed ? 

When you have a composition to write, choose 
some weed for a topic and use these questions as an 
outline for your guidance. 



PART II 

FRIENDS AND FOES AMONG THE 

INSECTS 




Cover Design for a Booklet on Insects 



The Booklets on Insects 



At least two insect booklets may be prepared by each pupil, one on In- 
sect Enemies and another on Insect Friends. The drawings and reports 
upon the Observations for Pupils suggested at the ends of the chapters will 
furnish abundant material for voluminous booklets. 

In making drawings of insects so as to show a back view with each side 
symmetrical, a butterfly with wings spread, for example, it is best to draw 
one half beside a straight line, then to transfer this half by means of tracing 
paper to the other side of the line. It is easier thus to get both sides alike. 



CHAPTER VI 
Orthoptera : the Grasshoppers, Crickets, and Cockroaches 

The Grasshoppers, Crickets, Cockroaches, Walking 
Sticks, and a few other species make up the order of straight- 
winged insects called Orthoptera. Practically all of them 
are injurious, or capable of becoming so. With the excep- 
tion of the Tree Crickets and the Mantids few of them are 
likely to be of great service to man, except possibly as a 
source of food to poultry. 

The insects of this order are characterized by having 
biting mouth parts, incomplete transformations, and four 
wings — the front pair usually being thickened, while the 
hind pair are membranous and folded like a fan beneath 
the front ones. This is a comparatively small group, but 
one in which there are some very destructive species. In 
America the Rocky Mountain Locust has done enormous 
damage. In the Old World the locust plagues of both an- 
cient and modern times were due to insects belonging to 
this order. 

Structure of a Grasshopper 

If you examine a grasshopper carefully, one of the first 
things you notice is that the body is divided into three im- 
portant sections. At the front end is the head ; next to 
this are two closely connected parts that bear the legs 
and wings and together form the thorax ; next to the thorax 
is a part divided into rings — the abdomen. 

65 



66 



FARM FRIENDS AND FARM FOES 




Mouth Parts of Grasshopper 

a, labrum ; b, mandible ; c, tongue ; d, maxilla ; e , la- 
bium. Magnified. 



The head varies greatly in shape with different species 
of grasshoppers, but in general it is larger above than be- 
low. From near the middle of the front there project two 
slender feelers or antenna, each of which is composed of 

a number of dis- 
tinct rings or 
segments joined 
together. Just 
above the base 
of each antenna 
is a large com- 
pound eye, the surface of which through a lens resembles 
the surface of a honeycomb. Each eye has a great number 
of hexagonal divisions : these are the facets which make 
up the compound eye. There are three simple eyes on the 
grasshopper's head — two between the compound eyes and 
one in the middle line above. These are very different in 
structure from the compound eyes, being merely small, 
round, lenslike objects. These simple eyes are often 
called ocelli. 

Below are the mouth parts of the grasshopper. Begin- 
ning from above, we see first a large four-sided flap or lip, 
which moves up - 
and down on a <mmMBil]^ 
basal hinge ; this 
is the upper lip 
or labrum. Be- 
neath it there is a pair of rather large jaws or mandibles 
attached so as to move sideways, and having sharp, toothed, 
cutting edges. On the inside of the mouth between the 
mandibles is the tongue ; and below this are the second 
jaws or maxilla, while still lower is the underlip or labium, 
with its labial palps or feelers. 




Nymph 



GRASSHOPPER 



Adult 



GRASSHOPPERS AND CRICKETS 



67 




Oblong Leaf-winged Grasshopper 



Directly back of the head, there is a large capelike seg- 
ment bearing a pair of legs. This is the first division of 
the thorax, and is called the prothorax. The remainder 
of the thorax is made up of two parts united. The one in 
the middle is the mesothorax ; this bears the front wings 
and the middle 
legs. Behind this 
is the metatJiorax ; 
this bears the hind 
wings and the hind 
legs. 

The front wings 
are long and slen- 
der, and when at rest serve as a protective covering to the 
hind wings. The latter are then folded in longitudinal 
plaits like a fan. When the grasshopper is flying, the front 
wings are extended at right angles to the body, and the 
hind wings are stretched out. 

The abdomen is composed of a number of joints or seg- 
ments, which move freely upon one another at their points 
of contact. In female specimens the abdomen ends in 
four-pointed projections by means of which the hole in the 
ground for the eggs is made ; these form the ovipositor or 
egg-depositor. 

Short-horned Locusts 

The common Grasshoppers or short-horned Locusts form 
one of the most important families (Acridiidae). These 
have short antennae or " feelers," short ovipositors, and but 
three joints to the tarsi — the short joints at the ends of 
the legs. They feed upon grasses and other forage crops, 
and are often very destructive. In many of the males, 
there is a sound-producing apparatus. 



68 



FARM FRIENDS AND FARM FOES 




Common Cricket 
Female 



The Red-legged Locust is one of the commonest 
members of this family. Its eggs are laid in the ground 

early in autumn and remain there 
through the winter. The next sum- 
mer they hatch into small grasshoppers 
that resemble the adult in general ap- 
pearance, but of course are much 
smaller and have no wings. They 
molt or cast their skins several times 
during the next six weeks, and then 
they become full grown with well- 
developed wings. 

The famous Rocky Mountain Locust 
is very similar to the Red-legged spe- 
cies. Fortunately it is unable to de- 
velop continuously except at high al- 
titudes, such as the plateaus of the 
Rocky Mountains. Here it used to become so abundant 
that it was forced to migrate 
for food. At such times, enor- 
mous numbers of the grass- 
hoppers flew toward the Mis- 
sissippi Valley, where they 
fed upon all kinds of grasses 
and grains and many other 
plants. As they came sud- 
denly in enormous swarms, it 
was impossible to fight them 
successfully, and they often 
did great damage. 

There are many other spe- 
cies of grasshoppers belong- 
ing to this family, which are common and widely distrib- 





Tree Crickets 
Male above ; female below 



GRASSHOPPERS AND CRICKETS 69 

uted. The Carolina Locust is one of the most familiar. 
It is abundant along roadsides and may be known by its 
hind wings with yellow borders. The Bird Grasshopper 
is our largest species. 

Meadow Grasshoppers 

The more slender Meadow Grasshoppers or Long-horned 
locusts form another distinct family (Locustidae). These 
have long, slender antennae or "feelers," conspicuous, 
sword-shaped ovipositors, and four joints to the tarsi. 
Nearly all the members of this family are green in 
color. They live chiefly on grasses and other herbaceous 
plants, though some species are common in trees and 
shrubs. The Meadow Grasshoppers, the Katydids, and 
the wingless cricket-like Grasshoppers are the important 
members of this family. 

Cricket Family 

The family to which the Crickets belong is called the 
Gryllidae. These insects are characterized by having hind 
legs adapted to jumping, long, slender antennae, and hori- 
zontal wings with the outside edge turned down at a right 
angle to the main part. In most Crickets there are pecul- 
iar projections called stylets at the hind end of the body, 
and there is usually in the females a spear-shaped ovipos- 
itor. 

The principal types of Crickets are Tree Crickets, Black 
Crickets, and Mole Crickets. The first live on trees and 
shrubs above ground, the second on the ground, and the 
third in holes in the ground. In the case of the Black 
Crickets, eggs are deposited in the soil early in autumn 
and remain unhatched until the following season. Some 
specimens, however, are generally to be found in winter in 



7° 



FARM FRIENDS AND FARM FOES 



a half-grown condition, so that these insects may hibernate 

in two stages of their life. 

The Tree Crickets are generally greenish or whitish 

insects, living on the leaves and branches of trees, shrubs, 
and herbs. They feed upon plant lice or 
aphides, and thus differ in their food 
habits from most of the order. But they 
often do considerable damage to rasp- 
berry canes by depositing their eggs in 
long rows in the pith. Such canes are 
likely to split open and winter-kill. 

The Mole Crickets are among the most 
remarkable examples of insect life. They 
are perfectly adapted to an underground, 
burrowing life. The front legs are de- 
veloped into digging organs by means 
of which the insect can make a tunnel 
in the soil, through which the cylindri- 
cal body easily passes. They are brown 
in color, and their food consists of under- 
Mole cricket ground roots of various sorts. 




Cockroaches and Walking Sticks 

The Cockroaches (Blattidae) are characterized by their 
flattened forms, their legs fitted for running, their flat over- 
lapping front wings, and their long, bristlelike, many-jointed 
antennae. Many forms of Cockroaches are wingless, though 
the typical full-grown form has well-developed wings. 
These insects feed upon almost anything, being commonly 
found about kitchens and sheds, especially where there are 
water pipes. Some species are also found in the woods, 
under the bark of trees, where they feed upon a variety of 
materials. Probably the original home of all the species 



GRASSHOPPERS AND CRICKETS 71 

was in the forest. The eggs are deposited in curious little 
brown packets, that may often be found under the loose 
bark of fallen logs. 

The only other important members of the order Orthop- 
teraare the Walking Sticks, which occasionally are injurious, 
and the Mantids, which are generally useful in that they 
feed upon various sorts of destructive insects. 

OBSERVATIONS FOR PUPILS 

Short-horned Grasshoppers or True Locusts 

A ■ 

1. Get a few good-sized grasshcppers — the larger the better. Kill 
them in a cyanide bottle or by immersing in alcohol. Study the struc- 
ture carefully to see if you can make out all the details mentioned on 
pages 65-67 of this chapter. 

2. Collect a lot of grasshoppers in a meadow or pasture. How do 
the young differ from the adults ? Rear a few in a vivarium, feeding 
with clover or grass. 

3. Place a piece of sod in the bottom of a box or a wide glas cylin- 
der. Put a few full-grown grasshoppers in also. See if you get eggs 
laid. 

4. Look up some of these references : — 

The Insect Book, pages 332-335. American Insects, pages 136-147. Nature Bi- 
ographies, pages 89-95. Life Histories of American Insects, pag</s 67-81. 

B 

1. Write or tell a story with this title : The Life of a Grasshopper. 
Describe : — 

Where and when the eggs are laid. 

What the eggs look like. 

When the eggs hatch. 

What the young grasshoppers look like. 

The growth of the young grasshoppers. 

Their food. 

When they become full grown. 

2. Illustrate your story with sketches: if written, draw on paper ; if 
told, draw on the blackboard. 



72 FARM FRIENDS AND FARM FOES 



Long-horned or Meadow Grasshoppers 

i . Get a few Meadow Grasshoppers of different kinds and put in a 
vivarium. Feed with clovers or grasses. 

2. In what ways do these differ from the true locusts or common 
grasshoppers ? 

3. Watch to see if you can find out just how they sing. 

4. Look up some of these references : — 

The Insect Book, pages 336-340. American Insects, pages 149-156. Stories of 
Insect Life, Second Series, pages 6-10. 

Crickets 

1. Collect some Black Crickets and keep in a glass vivarium with sod 
in the bottom. Observe whether you can see them move their wings as 
they smg. See if you can get some to lay their eggs. 

2. You can generally get Tree Crickets in summer and autumn by 
beating branches of trees and shrubs over an open inverted umbrella. 
Keep some in a vivarium, providing aphides for them to feed upon. 

3. Look up some of these references : — 

The Insect Book, pages 341-344. American Insects, pages 157-161. Life His- 
tories of American Insects, pages 45-58. 

Walking Sticks 

1 . You can often get live Walking Sticks by beating branches over 
an umbrella. Keep in a vivarium and insert leafy twigs for food. 
Notice how quiet the insects remain by day. 

2. Look up these references : — 

The Insect Book, pages 323-325. Nature Biographies, pages 58-63. 



CHAPTER VII 



Hemiptera : The True Bugs 

While the word bug has been in common English use 
for a long time as applying to an insect of almost any kind, 
the entomologists restrict the word to a certain group of 
insects which they call Hemiptera or Half-winged Insects. 
The mouth parts of the members of this order are formed 
for sucking, and the transformations are incomplete, their 
life changes resembling those of the grasshoppers rather 
than those of the butterflies and moths. An immense 
number of noxious insects are included in this group, 
some of the most notorious being the Squash 
Bug, Chinch Bug, the various kinds of aph- 
ides or plant lice and of the scale insects or 
bark lice, the Periodical Cicada, and many 
other equally injurious pests. 

The life history of these insects is well il- 
lustrated by that of the common Black Squash 
Bug. This pest appears in the garden in 
early summer, and the females soon deposit 
their eggs upon the young squash plants. 
These eggs are small, rounded objects, more 
or less triangular in their general outline. In 
from six to fifteen days they hatch into tiny 
bugs, which grow into the form and size of the parents. 

The newly hatched Squash Bug is more brilliantly colored 
than at any later time in its life, and these colors make it 
very conspicuous against the green background of the 

73 




Squash Bug 
Magnified 



74 FARM FRIENDS AND FARM FOES 

leaves. The abdomen and the hind part of the thorax are 
light green ; the legs and feelers or antennae are a beauti- 
ful crimson ; the head and front part of the thorax are a 
light crimson ; while the margins of the eyes are darker. 
This brilliancy, however, lasts for a short time only. An 
hour after hatching, the crimson is noticeably darker, and 
in a few hours the insect is nearly black. 

The young Squash Bugs soon begin their attacks upon 
the plant by inserting their tiny beaks into the succulent 
tissues of the leaves. In their general habits they resem- 
ble the adults. After about three days of this feeding, the 
abdomen becomes noticeably swollen and the color some- 
what lighter. This is an indication that the period of 
molting has arrived. These young bugs are often called 
larva or nymphs. They now assume a quiet, stationary 
attitude. The process of molting begins by the splitting 
of the skin lengthwise along the middle of the back, the 
split extending along the thorax and the front of the abdo- 
men. The time required to complete this molting opera- 
tion varies greatly, but generally is not longer than an hour 
or two. 

A few hours after the first molt, when the bugs have 
taken on their normal color, they are considerably lighter 
than before. They are also more alert. They feed again 
upon the sap of the leaves for about nine days, when they 
undergo their second molt. After this has taken place, so 
that the nymph is in its third larval stage, the body is 
larger and flatter, with the margins more sharply defined 
and the color somewhat darker than in the second stage. 

The most notable difference shown by the insect in the 
fourth stage, which is entered upon by the third molt about 
eight days after the second, is the noticeable development 
of the wing pads. These become more conspicuous than 



HEMIPTERA: THE TRUE BUGS 75 

before. After living in this fourth stage for about a week, 
the insect molts for the fourth time, entering upon its fifth 
stage. It is now quite different in appearance, and is 
easily recognized as a full-grown nymph, — a condition 
analogous to the pupa state of butterflies and moths, in that 
it is the stage immediately preceding the adult. The 
wing pads are greatly enlarged, while the thorax is wid- 
ened and lengthened. The body is more rectangular and 
so similar to a mature bug that at a little distance it may 
readily be mistaken for the latter. 

The full-grown nymph lives in this fifth stage about 
nine days before the final molt, by which it matures into 
the adult Squash Bug. 

The Chinch Bug 

The Chinch Bug has a life history similar to that of the 
Squash Bug, but it does much more damage because it at- 
tacks the great grain crops — corn, wheat, oats, and simi- 
lar staples. The areas in which it occurs in greatest 
abundance are shown by the dots on the map below. It 
has been estimated that during the sixty years from 1850 to 
1910 the losses due to this insect exceeded $300,000000. 

The full-grown Chinch Bugs pass the win- 
ter in the shelter of thick grass, fallen leaves, 
or other protection, and come forth in the 
spring. They then scatter to such grain 
crops as they can find. Here they lay their 
eggs, one bug often laying four or five hun- 
dred eggs. The young bugs soon hatch and Chinch bug 
attack the grain plants by sucking the sap 
through their pointed beaks. When they are abundant, 
they actually hide much of the surface of the leaf or 
stalk, and of course kill the plants. 




76 FARM FRIENDS AND FARM FOES 

The young Chinch Bugs pass through a series of molts 
very similar to those of the Squash Bugs. Those that 
hatch from eggs laid in spring become full grown about 
midsummer or a little later. They then lay eggs for an- 
other brood. These become full-grown before winter and 
hibernate in such protection as they can find. 

The destruction of Chinch Bugs in their winter quarters 
is one of the most effective remedial measures. By burn- 




Areas over which the Chinch Bug occurs in Most Destructive 

Numbers 

ing over strips of grass lands along fences late in the fall 
or early in the spring, many bugs may be destroyed. They 
may also be attracted to strips or patches of trap crops, 
such as millet, wheat, or corn, where they may be plowed 
under or otherwise killed. They are often trapped in fur- 
rows and killed by spraying with kerosene. 

Under certain weather conditions these bugs may be 
killed in vast numbers by the Chinch Bug Fungus — a 
parasitic disease that spreads rapidly in moist air. This 



HEMIPTERA: THE TRUE BUGS 77 

disease has been propagated artificially and distributed 
over wide areas by state officials to good advantage. 

Harlequin Cabbage Bug 

Throughout the Southern states, the Harlequin Cab- 
bage Bug is one of the best-known insects. It is called 
by many common names, due to its abundance and its con- 
spicuous markings in red and black. It feeds freely upon 
a variety of plants, but is most destructive to cabbages. Its 
life history is very similar to that of the Squash Bug. The 
barrel-shaped eggs are laid in clusters, commonly in two 
rows of six eggs each. They soon hatch into small flat- 
tened bugs that bear a general resemblance to the adults, 
although, of course, they have neither wings nor wing 
pads. These young nymphs suck the sap from the leaves 
through their pointed beaks, and during the next month 
shed their skins four or five times before they reach 
maturity. There are several broods every year, and the 
winter is commonly passed in the adult condition. 

As the Harlequin Cabbage Bugs come from their winter 
quarters very early and are readily attracted to mustard, 
turnips, and other plants, it is generally practicable to use 
these as trap crops. By planting, for example, a few rows 
of mustard in the cabbage field, the bugs will be attracted to 
these plants and may be readily destroyed together with 
the plants by spraying with pure kerosene. The field will 
then be comparatively free from the pest, and those that 
come later may be subdued by hand picking. 

Cicadas or Harvest Flies 

The Harvest Flies or Cicadas (Cicadidae) are the largest 
insects belonging to the suborder Homoptera. Every one 
has heard during the hot days of midsummer and early 



78 FARM FRIENDS AND FARM FOES 

autumn, the strange, shrill noise of the common Harvest 
Fly, or Dog-day Cicada. This insect is present everywhere, 
and its curious song is one of the most striking and charac- 
teristic of summer sounds. 

The most famous member of this family, however, is the 
strangely interesting Periodical Cicada or Seventeen-year 
Locust. The adults of these insects appear in certain lo- 
calities at intervals of either thirteen or seventeen years. 
They may then be exceedingly numerous. At such times 
they deposit eggs in the twigs of trees. These eggs soon 
hatch into strange little larvae that drop to the ground and 
work their way through the soil until they find some roots 
of trees or shrubs. Here they remain feeding and growing 
very slowly for a long period of years. As already indi- 
cated, in some regions they complete their development in 
thirteen years and in others in seventeen years. By the 
end of this long time, the little larvae have become quite 
large, and are of the shape shown in the lower illustration 
on the next page. They now come to the surface of the 
soil and crawl up the trunk of some tree or shrub, where 
they emerge as adult cicadas. These are able to make a 
curious shrill noise, somewhat similar to that of the Dog- 
day Cicada, although in both species the ability to sing is 
confined to the males. When the insects are very abun- 
dant, the sound may become almost deafening. 

Leaf Hoppers 

If with a close-meshed insect net, you sweep diligently 
a few yards of meadow or pasture land, it is probable that 
the most abundant insects you find in the net will be the 
small, flattened, quick-jumping Leaf Hoppers (Jassoidea). 
These insects vie with the plant lice in their enormous 
numbers. They are likely to be present in any region. 



PERIODICAL 
CICADA 



Adult 




Adult emerqinq 
from pupa 



Full-qrown pupa 



8o FARM FRIENDS AND FARM FOES 

So many of them, however, live concealed in grass lands 

that most people have little knowledge of their abundance. 

They are nearly all quite small insects, but doubtless do a 

great deal more damage than is commonly attributed to 

them. They suck the sap from practically all kinds of 

. grains and grasses, and many infest trees, 

ddS^S& imi shrubs, and other plants. They are 

y^yy /WV c l° se ty related to the Tree Hoppers found 

* * * on the twigs of trees. 
Tree Hoppers „, ,. r , . r . r . 

1 he life history or many species of the 

grass-feeding Leaf Hoppers has been carefully studied. 
The eggs are laid in autumn in the grass blades and remain 
unhatched through the winter. In spring they hatch into 
tiny nymphs or larvae that suck the sap from new grass 
blades and gradually develop into adult Leaf Hoppers. 
During this process they generally molt or cast their skins 
four or five times, reaching maturity early in summer. 
There seem generally to be at least two broods of the grass- 
feeding Leaf Hoppers in a season. 

In cases of great injury by these grass-feeding Leaf 
Hoppers, it may be worth while to burn over the areas 
most badly infested in winter or early spring, and thus de- 
stroy the winter eggs. It has also been found that vast 
numbers of the adult insects may be killed by the use of a 
broad pan similar to the hopper-dozer often employed to 
destroy grasshoppers. If this pan is covered with kero- 
sene, tar, or some similar substance, the insects will be 
caught and killed. 

Many crop pests are found among the Leaf Hoppers 
that feed upon vines, shrubs, and trees. The Grape Leaf 
Hopper is one of the most destructive and widely distrib- 
uted of these. Its life history has been carefully worked 
out in New York, where it has been found that the adult 



HEMIPTERA: THE TRUE BUGS 81 

insects spend the winter under leaves and rubbish, or in 
some similar shelter. They come forth rather early in the 
spring and feed for two or three weeks upon the leaves of 
raspberries, strawberries, and other plants. Early in May, 
when the leaves of the grapes appear, these adult Leaf 
Hoppers fly to the vineyards and attack the developing 
foliage. They continue here for many weeks. The fe- 
males deposit their small, whitish eggs in the green tissues 
of the blades of the leaves, several eggs being inserted 
side by side. 

A fortnight later these eggs hatch into small larvae or 
nymphs that also suck the sap from the leaves and grad- 
ually develop, passing through five molts before they be- 
come mature. These young nymphs are able to run over 
the surface of the leaves, but they do not jump as do the 
fully developed Leaf Hoppers. They reach maturity dur- 
ing the latter part of the summer and continue present 
until October, when they seek shelter for the winter. 
There is thus normally but one brood in a year, although 
in more southern regions there are probably two broods. 

The most effective means of combating this insect are 
burning over the places of hibernation, destroying the 
nymphs with a solution of whale-oil soap at the rate of one 
pound to ten gallons of water, and trapping the adults upon 
sticky shields held temporarily beside the vines. 

The Apple-tree Leaf Hopper is another widely distrib- 
uted destructive species. Examples of this may be found 
on the under side of apple leaves at almost any time during 
the season. The Rose Leaf Hopper is another form that 
may practically always be found upon rosebushes, where 
the characteristic result of Leaf Hoppers' injury may be 
seen in the whitened spots on the upper surface of the 
leaf. 



82 FARM FRIENDS AND FARM FOES 

Jumping Plant Lice 

The Jumping Plant Lice (Psyllidae)are few in number of 
species, and with the exception of the Pear Psylla are of 
comparatively little economic importance. This Pear Psylla, 
however, often becomes a very serious pest, attacking pear 
trees in overwhelming numbers, and sucking out the sap 
to such an extent as to cause great injury. The adult 
insect, which is only about the size of an ordinary plant 
louse, passes the winter on the bark of pear trees, commonly 
more or less concealed within crevices. They deposit their 
eggs very early in spring, especially about the buds or 
upon the unfolding leaves. In two weeks or so, the eggs 
hatch into tiny larvae which attack the petioles of the 
leaves as well as their general surface. In about a month 
each larva reaches maturity, having molted five times 
during the process. There are several broods each year, 
the number doubtless varying with the locality. 

Like the aphides, these insects secrete a large amount 
of the so-called honey dew, which consists chiefly of the 
sap of the plant that has passed through the bodies of the 
insects. Where a pear tree is badly infested, this honey 
dew covers the leaves, often collecting in large drops, 
which are believed to act sometimes as lenses in condensing 
the sun's rays so as to burn the foliage beneath. Upon 
this honey dew, there also develops a black fungus that 
soon gives the leaves and fruit of the infested tree a strange 
blackened appearance. 

Scale Insects or Coccids 

The strange Scale Insects or Coccids (Coccidae) form one 
of the most important groups of the Homoptera. Many 
of these are commonly known as Bark Lice, because they 



HEMIPTERA: THE TRUE BUGS 



83 



are found so frequently upon the bark of trees. If you 
examine the twigs or leafy branches of some apple trees, 
you will probably find what look like miniature oyster 
shells upon the bark. These are ex- 
amples of the Oyster-shell Scale. If 
you will carefully pry up one of these 
tiny scales and look at its under side 
with a lens, you will probably find a 
large number of minute oval eggs. 
Early in summer, these eggs hatch into 
tiny insects that wander over the sur- 
face of the young bark. In a day or 
two, they fix themselves in one place 
by inserting their beaks into the tissues 
and sucking out the sap, where they re- 
main and gradually develop their scaly 
covering. 

One of the most destructive insects 
ever introduced into America belongs 
to this family. It is the notorious San 
Jose Scale, a pest that during recent 
years has attracted more attention from 
fruit growers than any other insect. 
It is especially dangerous because its presence is difficult 
to detect until it becomes sufficiently abundant to injure or 
kill the infested tree. It then appears as a curious scaly 
crust on the bark. When only a few are present, they are 
difficult to find, as they are simply small circular spots of 
much the same color as the bark, plainly seen only through 
a magnifying glass. 

The appearance of the individual scales is well shown 
in the pictures on the next page. Each scale is a 
small circular object, closely attached to the bark, not more 




Scale Insects on 
Rose 







■ '■> 



Much Magnified 





fa i 1 





Larva 



San Jose Scale 



j 



Infested Pear TwiG 

Magnified 



HEMIPTERA: THE TRUE BUGS 



85 



than one sixteenth of an inch in diameter, having a dark 
raised point near the center. At first these scales are 
likely to be scattered here and there over the bark, but as 
they increase in numbers, they are found nearer together, 
touching or overlapping one another. Finally, when they 
become very abundant, they make a thick scurfy layer, of 
a grayish color that obscures the natural color of the bark 
and is easily rubbed off with 
a knife. The presence of 
such a layer indicates that 
the sap from the bark is be- 
ing sucked out by millions 
of the insects, and that the 
health of the tree is being 
seriously impaired. 

The young scales that live 
through the winter develop 
in early spring into mature 
insects, and each of the fe- 
males may givebirth to about 
four hundred young. These arc tiny yellow creatures that 
crawl around for about a day before they finally fasten 
themselves to the bark by inserting their curious beaks to 
suck the sap. They then begin to secrete the scale which 
is so characteristic of this family of insects. The scale is 
composed of white waxy threads secreted by the skin of 
the larvae, which mat together to form a rather dense 
covering. This whitish scale turns gray or even almost 
black within a few days. The female scales are always 
wingless, but the male scales develop into active two-winged 
insects which are able to fly about. 

When the San Jose Scale appears upon older trees, it is 
most likely to be found on twigs and smaller limbs, but 




BLACK SCALE 



86 FARM FRIENDS AND FARM FOES 

upon young trees it may occur over the whole surface of 
the bark. It does not confine its attacks to the bark, how- 
ever, for leaves and fruit are often infested. Upon these, 
as well as upon young bark, there is frequently a very 
characteristic purplish ring around each scale. When the 
leaves are infested, the insects are especially likely to be 
found along the midrib. 

This scale has commonly been introduced into new 
localities by means of young trees from nurseries. There 
are now rigid inspection laws in nearly all the states to 
prevent the further distribution of the pest in this way. 
The most effective remedy so far discovered, is that of 
spraying in late autumn with a miscibleoil or a lime-sulphur 
wash. As is so often the case, the use of this lime-sulphur 
wash has been found to have additional advantages in de 7 
stroying other insects and in preventing various fungous 
diseases. 

The Cottony Maple Scale is one of the most distinctive 
members of the great family of Bark Lice. It may be 
found in vast numbers, especially in the Middle Western 
states, upon the twigs of the silver maple, and is easily 
recognized by the mass of cottony tufts which are found 
beneath each of the darker-colored scales. Early in sum- 
mer great numbers of eggs are deposited inside of these 
cottony masses. About three thousand eggs commonly 
occur beneath each scale. In June or July these eggs 
hatch into tiny larvae that wander over the leaves and soon 
fix themselves, inserting their beaks to suck the liquid 
from the tissues. Here they continue to develop until 
shortly before the time for the leaves to fall. By this time, 
the males mature into small winged insects that are able 
to desert the leaves and fly about. The females, however, 
crawl from the leaves to the bark of the neighboring twigs, 






HEMIPTERA: THE TRUE BUGS 87 

upon which they fix themselves and secrete a larger scale. 
They remain on the twigs through the winter, and the 
following spring complete their growth, produce the 
cottony mass within which they lay their eggs, and finally 
die. There is thus but one brood each year. Fortunately 
this insect, as well as most other members of this family, is 
commonly kept in check by its parasitic and other enemies. 
The most important of these are small, black, four-winged 
chalcid flies and various species of ladybird beetles. 

The Aphides or Plant Lice 

From the point of view of their destructiveness, the 
Aphides or Plant Lice form one of the most important 
families, not only of the true bugs, but of all insects. 
During very recent years a single species affecting grain 
has caused a loss of more than a million dollars in one 
state in a single year. There are a great many species of 
these little pests, of which the Green Flies of house plants 
are familiar examples. They infest nearly all kinds of 
crops, sucking the sap through their pointed beaks and 
often causing enormous losses. 

The life histories of the various species of Aphides are 
quite similar. A good illustration is found in that of the 
Spring-grain Aphis which has attracted much attention on 
account of its damage to grain crops. Pictures of its vari- 
ous stages much magnified are shown on the next page. 
In many localities, it has been known as the "Green Bug." 
It is especially abundant in the more southern rather than 
the far northern states. 

Under normal conditions the Spring-grain Aphis passes 
the winter in the condition of the egg, attached to leaves or 
stalks of various grains and grasses. Early in the spring, 
these eggs hatch into small plant lice that suck the sap 



88 



FARM FRIENDS AND FARM FOES 



from the food plants and become full-grown in a very 
short time, possibly a week or ten days. All of these 
insects that thus hatch from the winter eggs are what are 
known as viviparous females, because they are able to give 






PupA 



Larva 

SPRING GRAIN-APHIS W|NGLESS 

[Redrawn from Webster] Female 




Female 



birth to living young. Each insect produces a large 
number of these young plant lice of the second generation, 
and these in turn very quickly mature and give birth to a 
third generation. This method of reproduction continues 
throughout the spring, summer, and early autumn. On 
account of the rapid growth and of the large number of 
young produced by each of the viviparous females, the 
insect is able to multiply with astounding rapidity. 

When the food plant is green and succulent, nearly all 



HEMIPTERA: THE TRUE BUGS 89 

the aphides are wingless forms, but when for any reason 
the condition of the food plant is less favorable to the 
development of the plant lice, large numbers of winged 
viviparous females are developed. These are often called 
winged migrants, because so many of them fly away to other 
fields where they settle upon new plants and there give 
birth to living young. In this way the insect commonly 
spreads from field to field, and when it has wintered in the 
South, it may gradually spread northward to infest new 
localities. 

When the grain crop ripens, the aphides usually migrate 
to various kinds of grasses, where they continue to develop 
throughout the summer, and migrate back again in autumn 
to fields of young grain. In these fields they continue to 
reproduce in the same viviparous manner until the approach 
of cold weather. At this time a sexual generation is devel- 
oped, the males commonly being winged, while the females 
are wingless. The winter eggs are laid by these females, 
and thus the yearly cycle is completed. 

When the winters are mild, it very often happens that 
this Grain Aphis is able to continue to develop through- 
out the winter in its viviparous condition, so that in a given 
locality we may have it passing the winter both in the 
egg state and in that of various ages of viviparous females. 
It is under such conditions that the greatest damage is 
likely to occur, especially because of the fact that the in- 
sects are able to thrive and multiply in a lower temperature 
than is favorable to the development of the tiny parasitic 
flies that commonly keep them in check. 

An even more interesting life history is that of a closely 
related plant louse known as the European Grain Aphis. 
This insect is abundant and very generally distributed in 
America. Its special point of interest is that it develops 



go FARM FRIENDS AND FARM FOES 

in summer on various grains and grasses, and migrates in 
autumn to apple trees, where the winter eggs are laid. 
Consequently, when we attempt to follow its history through 
the year, we may begin in early spring with these eggs 
upon the buds and bark of apple twigs, with this summary 
as a result : — 

In early spring the eggs hatch into small aphides that 
crawl at once to the developing buds where they begin to 
suck the juices of the unfolding leaves. In a few days, 
this first generation from the egg, often called the stem- 
mothers, begin giving birth to living young that also suck 
the sap from the leaves and soon become mature. In this 
way, four or five generations may develop on the apple in 
spring. A large proportion of the later generations are 
winged females, which fly away to settle upon grasses and 
grains and start colonies upon these host plants. Conse- 
quently these are called winged migrants. As a rule, all 
of the plant lice of this species thus desert the apple before 
midsummer. 

The winged migrants upon grains and grasses establish 
colonies that continue to increase throughout the remain- 
der of the summer upon these food plants, one generation 
following another in rapid succession. Rather early in 
autumn, however, a generation of winged females, called 
the return migrants, is developed from the grain and grass- 
feeding colonies. These return to the apple, where they 
give birth to a generation of wingless egg-laying aphides, 
by which the winter eggs are laid upon twigs. 

There are various other species of aphides which may be 
found upon the leaves of the apple. The presence of these 
other species has rendered the working out of the life his- 
tory of this European Grain Aphis a much more difficult 
problem than might at first appear. 



HEMIPTERA: THE TRUE BUGS 



9 1 




EGGS 
APPLE APHIS 



It was formerly supposed that to a large extent each 
kind of plant was subject to attack by a special kind of 
plant louse, but after careful studies were made of the 
structure and life histories of the plant lice, it was found 
that very often a single species 
of the insects may attack sev- 
eral species of plants. One of 
the most striking examples of 
this ability to live upon various 
host plants is that of the Melon 
Aphis, which infests an extraor- 
dinary variety of host plants. 
These include vegetable, field, 
and fruit crops, as well as many 
cultivated flowers and an extraor- 
dinary number of weeds and 
other wild plants. It has been 
known by such common names 
as Cotton Aphis, Orange Aphis, 
and Dock Aphis. It is so com- 
monly destructive to melons, cu- 
cumbers, and related plants that 
it is now generally called the 
Melon Aphis, although in cotton-growing regions it is 
known as the Cotton Aphis. 

The life history of this insect is not very different from 
that of the Spring-grain Aphis already described. The 
winter is passed both in the egg state and in that of the 
viviparous females. Reproduction begins early in spring 
and continues throughout the season, the insects multiply- 
ing with marvelous rapidity and migrating from time to time 
from one food plant to another. The ability of the species 
to develop upon so great a variety of hosts renders it 




92 



FARM FRIENDS AND FARM FOES 



easy for the migrating females to find suitable food, and it 
also renders the pest very difficult to fight successfully. 

Ants and Aphides 

One of the most interesting things about the aphides is 
their relation to various kinds of ants. If you look at a 
colony of plant lice upon almost any tree or shrub, you will 
probably find at least one kind of ant wandering around 
among the aphides, and very likely you will find a regular 

procession of ants go- 
ing up and down the 
trunk of the tree or 
shrub. If you watch 
one of these ants care- 
fully, you will probably 
see it find a plant louse, 
touch it with the feelers 
or antennae and very 
likely lap up a drop of 
liquid exuded by the 
aphis, for these ants 
visit the plant lice to obtain the liquids that pass through 
their bodies. In consequence, the plant lice are sometimes 
referred to as the milch cows of the ants. 

There are many strange and interesting things to be found 
out concerning the relations of the ants and the aphides. 
To a very large extent, many species of aphides find friendly 
helpers in the ants. One of the most interesting examples 
of this is the case of the Corn-root Aphis, an insect often 
very destructive to corn crops in the Mississippi Valley. 

This Corn-root Aphis is constantly attended by a small 
brown ant that burrows out tunnels along the corn roots in 
order that the plant lice may have a place to live. As the 




Ant attending Aphides upon a Willow 
Twig 



HEMIPTERA: THE TRUE BUGS 



93 



numbers of the plant lice increase, the ants extend the 
burrows to provide for them. The ants continue thus to 
look after the needs of the aphides throughout the summer 
months. In autumn, however, a still more interesting thing 
takes place, for at this time an egg-laying brood of aphides 
is developed and the small blackish eggs are taken by the 
ants far down in their underground nests, where the eggs 
are cared for throughout the winter. When the eggs hatch 
early the following spring, the young plant lice are carried 
by the ants, generally to the roots of some grass-like weed, 
there to start the new season's brood, which will be trans- 
ferred later to the roots of the young corn plants. 

In a case like that of the Cornroot Aphis, where the 
eggs of the insect pass the winter in the cornfield, rotation 
of crops is the best means of reducing injury by the pest. 
It is fortunate that there are great numbers of enemies of 
aphides in general, for otherwise it would probably be im- 
possible to grow many crops now produced. Many birds 
feed freely upon the eggs and later stages of aphides, while 
vast numbers of predaceous and parasitic insects develop at 
their expense. The insecticides that are most effective in 
destroying plant lice are kerosene emulsion, whale-oil soap, 
and various decoctions and extracts from tobacco stems. 




Elm Leaf affected by Aphides 



94 FARM FRIENDS AND FARM FOES 

OBSERVATIONS FOR PUPILS 
Squash Bug 

i. To what extent are these insects troublesome in your locality ? 

2. What plants do they attack ? 

3. What methods are used to kill them ? 

4. Try placing shingles or small boards about the hills to see if the 
bugs seek their shelter at night. 

5. Make a drawing of the Squash Bug for your insect booklet. 
Read : — 

The Common Squash Bug, U. S. Bureau of Entomology, Circular 39. 

Harlequin Cabbage Bug 

1. Is this insect common in your region? 

2. What plants have you known it to feed upon? 

3. Have you seen the eggs? Where were they laid? 

4. What remedies have you known to be used against Harlequin 
Cabbage Bugs? 

Cicadas or Harvest Flies 

1. Have your ever known an outbreak of the Periodical Cicada? If 
not, ask your friends about such outbreaks. 

2. Do you know the song of the common cicada? How often do 
you hear it? Is it more likely to be heard on hot or cool days? Did 

. you ever see one of the cicadas on a tree ? 

3. Read some of these accounts of cicadas : — 

American Insects, pages 166-168. Stories of Insect Life, Second Series, 
pages 1-5. 

Leaf Hoppers 

1. Look on the under sides of the leaves of trees, shrubs, and herbs 
to find leaf hoppers. Are they of different sizes and colors? You can 
get many of them by sweeping grasses and herbage with an insect net 
or by beating branches over an open inverted umbrella. 

2. You will readily find the earlier stages of the leaf hoppers on many 
leaves. Are the wings developed? Can the young hoppers jump like 
the adults? 



HEMIPTERA: THE TRUE BUGS 



95 



Bark Lice or Scale Insects 

i. Look on apple twigs for the characteristic scales of the Oyster- 
shell Scale. Pry up a scale and look on the under side with a lens. 
In the fall, winter, or early spring you are likely to find many eggs. 

2. Examine various fruit trees, especially 
peaches, plums, and pears, for the San Jose 
Scale. If found, learn whether the trees 
have been sprayed to destroy them. In 
autumn the scales are likely to be found 
upon the fruits. 

3. Examine other trees and shrubs for 
other scale insects. In order to learn their 
names, send such as you find to the Bureau 
of Entomology, U. S. Department of Agri- 
culture, Washington, D.C., with a letter 
telling on what plant you found them. 

Aphides or Plant Lice 

1. You generally can find these insects 
with very little trouble. Look on the leaves 
of apple or other fruit trees, or on willows or 
other trees. Look also on the leaves of 
flowers and vegetables. Do all the different 
kinds of aphides you find look alike? 

2. In fall and winter look on the bark 
of the willow branches and about the buds 
of apple trees to find the winter eggs of the 
aphides. Examine them through a lens and make a sketch for your insect 
booklet. 

3. Many aphides live in gall-like modifications of the leaves. Make 
sketches of such of these as you can find. 

4. Read one or more of these references : — 

American Insects, pages 171-176. Life Histories of American Insects, pages 
209-247. 




Cicada emerging from 
Nymph Skin 



CHAPTER VIII 



The Butterflies and Moths 



The great order of insects to which the butterflies arid 
moths belong is called Lepidoptera, a word meaning scale- 
winged. This name was given to the group because each 
of the beautiful wings with their varied colors and markings 
is composed of a thin membrane, to which are attached 

vast numbers of tiny scales over- 
lapping one another, much like the 
shingles of a house. The insects 
of this order have sucking mouth 
parts and two pairs of wings. The 
transformations are complete. The 
period of growth and feeding is 
that of the larva or caterpillar, the 
adults eating only the nectar of 
flowers or similar substances, or, 
in some cases, taking no food at 
all. 

This order includes a large num- 
ber of species, varying greatly in 
size and habits. Some of the moths 
are so tiny as to be barely visible 
to the unaided eye, while others are so large and conspic- 
uous as to attract attention at considerable distances. By 
far the largest proportion of the species feed in the larval 
state upon the tissues of plants, and consequently a great 
many injurious insects are found in the order. 

96 







Promethea Moth Cocoon 



THE BUTTERFLIES AND MOTHS 



The Butterflies 



97 



The highest group of the Lepidoptera is the great super- 
family to which the butterflies belong ; this is commonly 
called the Papilionina. This includes four distinct families 
which need not be considered specifically here. 

The butterflies as a group are day-flying insects, with 
knobbed antennas or ■" feelers," small bodies, and compara- 
tively large wings. The caterpillars do not spin cocoons, 
changing to the pupa state as naked chrysalids, although 
often there is a loop of silk over the shoulders to hold the 
chrysalis in position. These caterpillars have three pairs 
of true legs and five pairs of prolegs. 

A familiar example of the life history of a butterfly is 
found in the common Cabbage Worm, the adult of which 
is the common white butterfly, with black spots upon the 
wings, which is to be seen flying about gardens throughout 
the summer. These butterflies lay eggs upon the cabbage 
leaves. The eggs soon hatch into small greenish larvae 
that feed upon the tissues of the leaf for a few weeks, 
molting or casting their skins four or five times during this 
period. When full grown, they find some sheltering leaf, 
stone, or board, beneath which they change to the chrysalis 
state, to emerge a short time later as adult butterflies. 

While as a group the butterflies have by no means as 
many injurious species as have the various groups of moths, 
a number of rather destructive insects belong to it. One 
of the most widespread of these is the Black Swallow-tail 
or Asterias Butterfly, the larvae of which feed upon the 
leaves of celery, carrots, parsnips, and various other mem- 
bers of the parsley family. These caterpillars are green, 
marked with black, and may very commonly be found upon 
the garden plants mentioned. Another species, which is 



9 8 



FARM FRIENDS AND FARM FOES 



often destructive, is the Mourning Cloak Butterfly, the 
caterpillars of which frequently defoliate willow, poplar, 
and elm trees, so that in some localities they are called the 
Spiny Elm Caterpillars. 

An even more generally destructive butterfly is the larg- 
est of our North American forms, called the Cresphontes 
Butterfly. This is a Southern species, being, however, 
widely distributed as far north as Massachusetts, New 




Orange-dog Caterpillars 



York, and Illinois. Throughout the orange-growing re- 
gions, the caterpillars are commonly known as " Orange- 
dogs," because they feed so largely upon the leaves of 



THE BUTTERFLIES AND MOTHS 99 

orange trees, being especially destructive to young plants 
in the nursery. They are curious-looking caterpillars, and 
doubtless their unusual appearance, possibly suggestive of 
a watchdog, has given rise to the common name. 

Briefly summarized, the life history of the Orange-dog 
Butterfly is this : The eggs are deposited singly upon the 




Butterfly of Orange-dog Caterpillar just emerged from Chrysalis 

young growth of the orange, generally near the tips of 
leaves or branches. In a week or more they hatch into 
tiny caterpillars that feed upon the tender foliage. When 
not eating they rest upon the lower surface of the leaves. 
In about a week, they become too large for the skin with 
which they were born, and they molt or cast their skin, 
coming forth with a new one that had been formed beneath 



ioo FARM FRIENDS AND FARM FOES 

the old. They then feed again for a week or so before 
molting for the second time. 

These processes of feeding and molting are commonly 
continued for four or five weeks, the caterpillars eating 
more and more of the leaves as they grow older. They no 
longer confine themselves to the succulent young leaves 
and shoots. A single insect may do much damage to a 
young tree, as it consumes a relatively large amount of the 
growing tissues of the plant. When full grown in the 
caterpillar stage, the insect changes to the chrysalis, gen- 
erally attaching itself by silken threads to the bark of a 
twig or branch of the orange tree. The chrysalis takes on 
the same general coloring as the surrounding bark, so that 
it becomes decidedly inconspicuous. In a little less than 
a fortnight it emerges as an adult butterfly. 

Like the caterpillars of the other Swallow-tail Butter- 
flies, these Orange-dogs have curious yellowish scent organs, 
which protrude from the upper surface just behind the 
head. When the caterpillar is disturbed, these give forth 
a very disagreeable odor, which is believed to serve as a 
means of repelling birds and possibly other enemies. At 
any rate, good observers have noticed that the insect is not 
molested by birds, although it is known to be subject to 
attack by various insect parasites. Each female butterfly, 
apparently, is able to deposit four or five hundred eggs, 
and one of the interesting ways suggested for preventing 
the injuries of the caterpillars is to shoot the butterflies 
upon the wing with cartridges loaded with sand or small 
bird shot. 

Sphinx Moths 

A beautiful family of the scale-winged insects is that of 
the Sphinx Moths or Sphingidae ; these are commonly 



THE BUTTERFLIES AND MOTHS 101 

called Hawk Moths. They are characterized by having 
large bodies, with small wings and very long curious 
tongues, which sometimes reach a length of five or six 
inches. Nearly all of them fly just at twilight, rather than 
during the day. The family includes a large number of 
species, several of which are injurious to cultivated crops. 

Most of the caterpillars of the Hawk Moths have the habit 
of assuming during the day a curious attitude, with the 
head end of the body held rigidly erect in a way suggestive 
of the famous Sphinx of Egypt. To this is doubtless due 
their common name of Sphinx Caterpillars. A familiar 
illustration of these larvae may be found late in summer on 
tomato, potato, tobacco, and related plants, for the common 
tomato and tobacco worms belong to this group. There 
are really two species of these tomato worms, one being 
more abundant in the North, and the other in the South. 
When full grown the caterpillars burrow into the soil, where 
they change to brown pupae, and early the following sum- 
mer wriggle to the surface of the soil, to emerge as beauti- 
ful grayish Hawk Moths. 

Another common, widely-distributed member of this 
family is the Pandorus Sphinx, the caterpillars of which 
are often injurious to grapevines and Virginia creepers 
or woodbines. The moth is large and beautiful, exquisitely 
colored in greens and browns. The eggs are laid early in 
summer upon the leaves of the food plant, hatching in a 
few days into small sphinx caterpillars that feed and molt 
for several weeks before becoming full grown. They are 
then three or four inches long, and the thickness of a man's 
finger. They now crawl to the ground and burrow into 
the soil a short distance, where they change to pupae, to 
remain until the following season, when they emerge as 
moths. 



102 



FARM FRIENDS AND FARM FOES 



Silk-spinning Moths 

One of the most important groups of the Lepidoptera 
is that of the silk-spinning moths (Bombycinae), of which 
the most famous is the silkworm of commerce. As a rule, 
the bodies of the Bombycine Moths are large and thick, 
and the mouth parts are generally inconspicuous or absent 
altogether. In the latter case the adult moth is unable to 
take any food, consequently these moths are seldom to be 
seen visiting flowers, as do the Hawk Moths and the Owlet 
Moths. The caterpillars are frequently thickly clothed 
with hairs, and they nearly always change to pupae within 

the protection of 
silken cocoons. 
The families of 
this group in- 
clude some of the 
insects most de- 
structive to vege- 
tation. 

The most beau- 
tiful American 
insects are the 
larger forms of 
the Bombycine 
Moths. The 
wonderful trans- 
lucent beauty of 
the Luna Moth, 
the handsome col- 

Luna Moth : Reduced 

oring of the Ce- 
cropia Moth, and the glorious browns of the Polyphemus 
Moth deservedly attract the attention of every one that sees 




THE BUTTERFLIES AND MOTHS 



103 



them. The curious cocoons of the Promethea Moth fas- 
tened so securely to the branches of many trees and shrubs 
may be found throughout the winter over a large part of 
North America, and, if brought indoors, will yield a har- 
vest of attractive moths in early summer. 

The familiar Tent Caterpillar, the nests of which are to 
be found in so 
many wild cherry 
and apple trees 
during May and 
June, is also a 
smaller example 
of one of these 
families of silk 
spinners. These 
Tent Caterpillars 
are very easily 
reared indoors, so 
that it is easy to 
watch them spin 
their cocoons, 
change to pupae, and emerge later as rather small brown 
moths. 

The most notorious member of the nearly related family 
of Tussock Moths is the destructive Gypsy Moth, which 
during the last few years has done enormous damage in 
New England, and millions of dollars have been spent in 
fighting it. This Gypsy Moth is a native of Europe and 
was introduced into America about 1869. Since then 
it has gradually spread from the Massachusetts town where 
it first escaped, and threatens to become one of the most 
widespread and destructive of insect pests. It is very 
desirable that people everywhere should be on the watch 




io4 



FARM FRIENDS AND FARM FOES 



for it, so that on its first appearance in a new locality it 
may be promptly exterminated. 

The adult Gypsy Moths appear upon the wing during 
the latter part of summer. The females are larger than 
the males, having a wing expanse of nearly three inches, 
and are of a whitish color. Their bodies are very large 
and heavy, so that the moth is able to fly only to a very 
slight extent. The male moths have a wing expanse of 
less than two inches, and are of a brownish-yellow color. 
Their bodies are slender, and the moths are able to fly 
readily. 

Soon after emerging from the cocoons, the female moths 
deposit their eggs in characteristic masses, each mass com- 
monly containing about five hundred eggs. They are very 
likely to be deposited in such hiding places as hollow trees 
or logs, or among the stones of stone walls. These eggs 
remain unhatched until about the time the leaves begin to 




LARVA 







GYPSY MOTH 




PUPA 



appear the following spring. Then they hatch into tiny 
caterpillars that feed upon the leaves. These grow rapidly, 
molting several times as the weeks go by, until finally they 
become full-grown hairy caterpillars that change to pupae 
within very slight silken cocoons, if, indeed, the few silken 



THE BUTTERFLIES AND MOTHS 105 

threads that commonly protect them may be called cocoons 
at all. A short time later they change again to adult 
moths. 

The special danger from these Gypsy Moths is due to the 
fact that they multiply so rapidly, feed so ravenously, and 
attack practically all kinds of growing plants, including even 
the coniferous evergreens. They are as yet comparatively 
little injured by birds or parasitic enemies, although every 
effort is being made by official entomologists to introduce 
into this country the various parasites that keep the species 
in check in Europe. 

The Fall Web-worm is a caterpillar easily found during 
late summer and early autumn. Its unsightly nests occur 
upon a great variety of fruit and shade trees. These Web- 
worms hatch from eggs laid in clusters upon the leaves by 
a whitish moth. The tiny caterpillars begin to spin a pro- 
tective web as soon as hatched. When very young they 
are yellowish, marked with black, and have a few hairs 
projecting from their bodies. They spin webs over the 
nearer leaves and then feed upon their green substance, 
eating this out so that the network of veins is left. As the 
days go by, they enlarge the web to cover other leaves, 
which are in turn attacked. They molt about once a week, 
remaining always beneath the protecting web. As they 
become full grown, the caterpillars eat more or less of the 
veins along with the leaf substance, but they generally avoid 
the midribs. 

The full-grown Web-worm caterpillars are a little more 
than an inch long, with the body densely clothed with 
yellowish hairs. They now leave the trees and descend to 
the ground. There they spin slight silken cocoons within 
which they change to the chrysalis state, and remain until 
the following June, when they emerge as moths to lay eggs 



106 FARM FRIENDS AND FARM FOES 

for another brood of Web-worms. There is thus but a single 
generation in a season. 

One of the most destructive moths that has ever ap- 
peared in America is the famous Brown-tail Moth, which 
has already done an enormous injury in New England, 
and which threatens to become widely distributed over the 
country. This pest seems to have been accidentally intro- 
duced with a shipment of nursery stock from Europe. It 
is especially troublesome not only because the caterpillars 
feed upon practically all kinds of deciduous trees, but also 
because their bodies are covered with poisonous hairs that 
cause great suffering when they get upon the human skin. 

The Brown-tail Moth passes the winter in characteristic 
nests composed of compact masses of leaves fastened to- 
gether by silken webs. Inside each of these nests, there 
are commonly several hundred tiny caterpillars. When 
spring comes, these little caterpillars leave the nests when 
they wish to feed, crawling along the twigs until they 
reach foliage. At first they return to the nests at night 
and when not feeding, but as they grow larger, they are 
likely to desert them altogether. They continue to feed 
and grow until about the middle of June. Each caterpillar 
then spins around itself a silken cocoon, which is attached 
to some convenient shelter, commonly the leaves of the 
food tree. Inside these cocoons, the caterpillars change to 
chrysalids, and three or four weeks later again change to 
the peculiar whitish moths, with a tuft of brown hairs at 
the end of the body of the females. This tuft gives the 
insect its common name. 

These moths appear in June, and lay eggs in clusters of 
two or three hundred each on the leaves, generally near 
the ends of the branches. During the latter part of the 
summer these eggs hatch into small caterpillars, which 



THE BUTTERFLIES AND MOTHS 107 

feed upon the leaves, forming gradually the protective 
nest that remains upon the trees through the winter. The 
caterpillars remain inside the webbed leaves, and thus 
wait until the following spring. 

An effective remedy for this insect is that of burning 
the winter nests. In localities where it is not yet found, a 
constant watch should be kept for it, and any suspicious- 
looking nests should be sent to the State Experiment 
Station for examination. 

Owlet Moths 

Another important family of the Lepidoptera is that of 
the Owlet Moths, or the Night-flying Moths (Noctuidae). 
These are comparatively small moths, having thick bodies, 
slender antennae, rather small wings, and for the most 
part inconspicuous colors. The larvae are generally 
smooth-bodied worms, that commonly transform into pupae 
in earthen cells. This group includes a large number of 
very destructive insects, of which the Army Worm and the 
Cutworms are good examples. 

For more than a hundred years, the Army Worm has 
been destructive to American crops. It is one of those 
insects which appear at irregular intervals in enormous 
numbers, and then suddenly disappear for many years. 
Briefly told, the story of the life of the individual Army 
Worm is this : — 

On some summer night there appears flying about a 
meadow, a rather large, light-brown moth. She finds a 
cluster of grass blades. Into the folded leaves of one or 
more of these, she pushes a number of small, whitish 
eggs, grouping them in rows of a dozen or more. A week 
or ten days later, each egg hatches into a minute whitish 
worm, that nibbles at the grass blades at night, and during 



io8 



FARM FRIENDS AND FARM FOES 






5L 



■^ '.'iM 



If 




Moth 



ARMY-WORM 



the day hides beneath the grass from the rays of 
the sweltering sun. 

This larva grows rapidly in size. At the end 
of a week it molts or casts its skin, a process in 

which the old 
skin splits open 
along the back, 
and the worm 
crawls outclothed 
in a new skin that 
has developed be- 
neath the old one. 
Again it feeds as 
before, its vo- 
racity increasing 
with its size. This 
molting is re- 
peated four or five 
times during the 
month after the 
eggs hatch, so 
that by the end 
of this period, the 
insect is one and 
a half inches long, 
and has the brown 
markings of the full-grown Army Worm. 

The instinct of the caterpillar now teaches it to seek 
more secure shelter for the helpless stage, upon which 
it is about to enter. It burrows into the soil an inch 
or less and wriggles about in the earth until it pro- 
duces a hollow cell. In this it casts its skin again and 
becomes a pupa — the third stage of its existence. When 



LARVA 



PUPA 



<&& 




THE BUTTERFLIES AND MOTHS 109 

the caterpillars are very abundant, many of them do not 
go into the ground, but change to pupae beneath whatever 
shelter may be at hand. About a fortnight later, another 
change takes place, and the fully developed moth emerges 
from the pupa, thus completing the cycle of the insect's 
life. The moths fly toward dusk and at night, and by 
means of their long tongues, coiled up when not in use, 
they suck the nectar of various flowers. 

During ordinary years the Army Worm is present in 
most of the regions where its outbreaks occur, individual 
caterpillars feeding in meadows and pasture lands, but the 
number is not sufficient to attract notice. At such times, 
their habits of life are very similar to those of the common 
Cutworm, to which, indeed, the Army Worm is closely re- 
lated. It is only when the caterpillars become so nu- 
merous that they exhaust the food supply of the field in 
which they develop, that the " army " habit is assumed. 
Then, however, they are forced to seek new quarters for 
food, and as their only mode of progress is by crawling 
along the ground, they move in solid masses toward ad- 
jacent fields. They feed preferably upon the various 
grasses and grains, although, when driven by hunger, they 
will eat the leaves of clover and other plants. 

One of the most effective means of preventing the in- 
juries of these armies of caterpillars is to dig a deep ditch 
or trench, into which the worms fall in great numbers, 
where they can be destroyed by various mechanical devices. 

The Cutworms form one of the most vexatious groups 
of injurious insects. They are the smooth-skinned, thick- 
bodied worms, an inch or so in length, which are so often 
to be found by careful digging about a tomato or cabbage 
plant that has been cut off in the night. They attack a 
great variety of crops and often cause serious losses. 



no FARM FRIENDS AND FARM FOES 

The Cutworms are the young or larvae of rather large 
millers, or night-flying moths of the family Noctuidae. One 
of them is represented natural size in the figure below. 
In the case of several of our common species — for there 

are many different kinds of Cutworms 
— these moths lay eggs in grass lands 
Cutworm Larva j a te in summer or early in autumn. 
The eggs soon hatch into small worms that feed upon the 
grass until cold weather, when they seek such shelter as 
can be found in the soil or rubbish at or near the surface 
of the soil, and remain quiet until spring. They are likely 
to be half grown when winter closes in. 

When the sunny days of April come, the Cutworms 
again begin to feed. If the grass land has been plowed, 
they eat such green things as they can find, until the corn 
or other crop comes up; then they feed upon it. If they 
are in grass near gardens, they are likely to wander over 
the garden more or less, taking such plants as they find. 
They travel at night, remaining concealed in or near the 
soil during the day. 

Toward the latter part of the spring the Cutworms be- 
come full grown in this larval state. They then burrow 
into the soil, and change to pupae or chrysalids of a 
brownish color. About two weeks later they again change 
to adult moths. 

Various remedies for Cutworms are known. In gardens, 
when a plant has been cut off, a prompt search of the soil 
about the base of the stem will generally reveal the worm, 
which may then be killed. On a larger scale, the use of a 
poisoned bait made by mixing a small amount of Paris 
green with bran or middlings, or a mixture of the two, has 
been successful. This is scattered upon the grass beside 
the field to be protected, or is placed in rows in the field 



THE BUTTERFLIES AND MOTHS 



in 



itself. But great care is of course necessary in such use 
of poisons. 

It is not often that an insect attacks three crops which 
are so different in every way as cotton, corn, and tomatoes. 
This is the case, however, with the noctuid moth, known 
by the various names of Bollworm, Corn Worm, and To- 
mato Fruit Worm. The cater- 
pillars have a general resemblance 
to some of the commoner cut- 
worms, although they vary greatly 
in color and markings. In the 
Southern states, these caterpillars 
feed to a destructive extent upon 
the bolls of cotton, on account of 
which they are called Bollworms. 
In regions farther north, these 
caterpillars feed inside the husks 
of green corn, upon the tassels and 
immature kernels, on account of 
Which they are commonly called 
Corn Worms or Tassel Worms. 

In some regions where tomatoes are largely grown, these 
caterpillars feed upon the green fruit, often boring into it 
in a very destructive manner ; consequently, they have re- 
ceived the name Tomato Fruit Worm. In the South, how- 
ever, the insect does not confine its attention to cotton, for 
it often feeds also upon green corn even in cotton-growing 
regions. 

As a Corn Worm, the life history of this insect may be 
summarized in these words : The adult yellowish or yel- 
lowish-green moths appear in the cornfield early in the 
summer and deposit their eggs upon the leaves or stalks 
of the growing plants. Four or five days later these eggs 




Cotton Bollworm 



H2 FARM FRIENDS AND FARM FOES 

hatch into small caterpillars that commonly hunt until they 
find the end of a young ear of corn, where they feed upon 
the green tassels and gradually burrow beneath the husks, 
eating both tassels and young kernels as they proceed. 
When once beneath the protection of the outer husks, they 
remain until they become full grown. They are then a 
little over an inch long. Each makes a round hole through 
the husk and enters the soil below the plant, where within 
an oval cell it changes to a pupa. Some time later it 
again changes to an adult moth. 

The life history of the insect when it feeds upon cotton 
is very similar, except that the young cotton bolls are at- 
tacked instead of the ears of corn. An interesting fact in 
regard to the species is that in the more northern regions 
this insect does not seem to be able to survive the winter 
in any stage. Consequently, it is believed that most of 
the injury there done each season is caused by moths that 
fly northward from the south. 

The Larger Cornstalk-borer, which is also known as the 
Sugarcane-borer, is one of the most generally destructive 
insects in the Southern states. Early in spring, about the 
time the young corn plants are four or five inches high, a 
rather small moth appears in the fields and lays eggs upon 
the leaves of the young corn plants. These eggs soon hatch 
into small caterpillars that burrow into the stalk until they 
reach the pith. Then they begin feeding upon this pith, 
usually burrowing upward. They continue to feed and 
grow for several weeks, often coming out of the original 
plant and burrowing into a neighboring one. About mid- 
summer, they become full grown in the larval state. Then 
they change to pupae inside the tunnels within the corn- 
stalks, to emerge a fortnight later as adult moths. 

These moths lay eggs for a second generation of cater- 



THE BUTTERFLIES AND MOTHS 



"3 



pillars, that burrow into the cornstalks in the same way, 
and usually remain through the winter in their tunnels with- 
out transforming to pupae. Early in spring, however, this 
transformation takes place, and the moths appear in time 
to lay their eggs upon the young corn plants of a new 
season. 

This Cornstalk-borer is especially destructive in regions 
where old cornstalks are left in the field through the winter. 
The destruction of these, with the hibernating caterpillars 
inside, will very largely reduce the injury the following 
season. It is another one of the numerous insects which 
point the moral that " good agriculture is the first and best 
insecticide." 

Codling Moth 

It is more than a century since the Codling Moth or 
Apple Worm began to prey upon the fruit of American 
orchards. This pest was 
introduced from Europe 
early in our history. Its 
life history in brief is 
this : — 

The parent insect is 
a small chocolate-brown 
moth, scarcely half an 
inch long, which appears 
among the trees in spring 
about the time the young 
apples are forming. The 
tiny whitish eggs are de- 
posited upon the fruit, 
stems, or leaves. These eggs shortly hatch into small larvae 
that commonly enter the blossom end of the apple, where 



CODLING 
MOTH 




ii4 



FARM FRIENDS AND FARM FOES 



they are likely to nibble for a few days before they burrow 
down toward the core. When once within the fruit, they 
feed and grow for about a month. Then they leave the 
fruit and find shelter where they spin their cocoons, within 
which they change to pupae. Each insect remains in this 
pupal state for about two weeks ; then it emerges as an 

adult moth, like the 
one that laid the 
original eggs. 

These moths com- 
monly lay eggs for 
a second brood of 
worms, that de- 
velop in the apples 
throughout the late 
summer or early au- 
tumn months. The 
larvae leave the ap- 
ples when full grown 
and, in the shelter of rough bark or something similar, spin 
silken cocoons, within which they remain until about the 
time the apples blossom the following spring. Then they 
change to pupae, and change again in about two weeks to 
adult moths. There are two broods of these moths a year, 
each distributed over a long period. 

The injuries of the Codling Moth larvae may be pre- 
vented to a large degree by spraying with arsenical poisons 
in spring, soon after the petals of the blossoms have fallen. 
It is especially desirable that a thorough spraying be given 
before the calyx end of the young apple is closed. In the 
picture above, the calyx in each of the outer fruits is open ; 
that of the larger, middle fruit is closed. By means of the 
spraying machine, the fruit grower is able to place in the 




Apples Showing Calyx Open and Calyx 
Closed 



THE BUTTERFLIES AND MOTHS 115 

upper or blossom end of the apple a few particles of poison, 
so that when the newly hatched worm nibbles at the skin, 
it is likely to eat one or more of these particles and be killed. 
Two sprayings are generally desirable ; the first less than a 
week after the petals fall, and the second ten days or two 
weeks after the first. 

Leaf Rollers and Leaf Miners 

Examples of the great group of Leaf Rollers, several 
families of which are commonly classed together into one 
superfamily (Tortricina), are easily found wherever there 
are trees or shrubs in variety. These insects are espe- 
cially characterized by the ability of the 
larvae to fasten together the edges of 
leaves by means of silken threads. 
Sometimes it will be a single leaf 

cleverly rolled into a tube, and at other 

/ . Leaf Roller Moth 

times it will be a number of leaves upon 
the same branch, sewed together to make a tent. In 
either case, the leaves thus united are utilized as a home 
for the young caterpillars, that feed upon the green sub- 
stance on the inside, and so escape, to a large extent, the 
attacks of birds. 

When fully grown, the caterpillars change to pupae, 
either in the webbed home or in some other shelter, and 
a little later they change again into small moths. One of 
the commonest examples of this great group is the so- 
called Rose Leaf Roller, which is also often found upon 
the leaves of apple and many other trees Fortunately in 
the case of most Leaf Rollers, the protecting web does 
not prevent the access of parasitic flies which destroy the 
caterpillars in great numbers. 

The smallest of the scale-winged insects belong to the 




n6 FARM FRIENDS AND FARM FOES 

great group of Leaf Miners (Tineina). For the most 
part, these insects in their larval stages live between the 
upper and lower surfaces of leaves as true miners. Some 
of them, however, have other habits. A comparatively 
small number make tiny silken cases which serve as houses 
within which they live. Others burrow in fruits, stems, 
or seeds. Still others feed upon wool or furs or feathers ; 
the common clothes moths are illustrations of these. 

If you will look carefully at the leaves of the nearest 
apple tree, you will be likely to find illustrations of the true 
Leaf Miners. Several distinct species live upon the tissues 
of apple leaves. One of the commonest is the Apple-leaf 
Trumpet Miner, which is easily recognized by the curious 
trumpet shape of the yellowish mine that is conspicuous 
within the green tissues of the leaf. The life history of 
this species is very simple. A small brown moth lays her 
Qgg upon the surface of the leaf. The Qgg shortly hatches 
into a tiny larva, that burrows through the skin of the leaf 
and feeds upon the green cells inside. Here it continues 
to feed and grow for some weeks, casting its skin occasion- 
ally. It remains as a larva within the mines when the 
leaves fall in autumn. In the spring it changes to a pupa, 
still within the fallen leaf, and a little later the moth 
emerges. This insect is sometimes so numerous as seri- 
ously to injure the foliage of the trees. 

Peach-twig Borer 

The insect which in California is known as the Peach 
Worm and which in many other parts of the country is 
called the Peach-twig Borer, is one of the most extraor- 
dinary of fruit insects. This is due to the remarkable varia- 
tion of the habits of the larvae in the three different broods 
developed during each year. 



THE BUTTERFLIES AND MOTHS 



117 




Peach-twig Borer : Winter Burrow 
Cut Open 



The life history of this pest in California has been very 
carefully worked out by the investigators of the State Ex- 
periment Station. In brief it is as follows: Throughout 
the fall and winter the small caterpillars are hidden within 
curious cells that they make in the bark of the trees, es- 
pecially in the forks of 
the branches. These lit- 
tle burrows are furnished 
with a silken lining, and 
are covered with a sort 
of thatch made by fasten- 
ing tiny bits of bark to- 
gether with silk. Within 
these hibernating cells, 
the insects are protected 
from most dangers. Early 

in spring, the larvae become active and get ready to emerge 
from their winter quarters by tearing away a part of the 
protective covering. Finally they emerge and attack the 
young buds, burrowing their way into the pith of the short 
branches. They thus become twig borers, and often do 
great damage. 

After a few weeks of this existence, they hide within the 
bits of curled bark upon the trunk and larger branches, 
where they change to pupae, generally very slightly shel- 
tered by a few silken hairs. These pupae shortly change 
again into adult moths, that lay their eggs on the bark of 
the young twigs. These eggs soon hatch into tiny larvae, 
which also become twig borers during the first weeks of 
their life, usually upon a tree loaded with fruit. This brood 
of worms lives as twig borers for only about three weeks. 

They then leave the twigs and burrow into the green 
peaches, entering at the stem end and feeding freely upon 



n8 FARM FRIENDS AND FARM FOES 

the green pulp. Here they continue until they become 
full-grown as larvae, often doing an enormous amount of 
damage to the peach crop. Finally they emerge from the 
fruits and change to pupae on the outside of the peach, 
generally in or near the stem cavity. A week later, these 
pupae change to moths that deposit their eggs upon the 
peaches, and these eggs hatch into worms that also burrow 
into the peach fruits, finally maturing and pupating on the 
outside of the fruits in the same way that the second 
generation did. 

A week later, the third brood of moths appears, generally 
during the latter part of August, and these deposit their 
eggs upon the bark of the trees. The larvae that hatch 
from this lot of eggs burrow immediately into the bark 
and hollow out the hibernating cells. 

There is thus in the extraordinary history of this Peach- 
twig Moth a series of three broods of larvae, one of which 
is exclusively a borer of bark and twigs, the second of 
which is both a twig borer and a fruit worm, and the third 
of which, on fruiting trees, is exclusively a fruit worm. It 
has been found that the hibernating worms may be de- 
stroyed by spraying the trees in spring with a lime, salt, 
and sulphur wash, and the injuries maybe prevented to a 
considerable extent by burying or covering the piles of 
wormy peaches. 




Tineid 7 \ Moth Jf 



THE BUTTERFLIES AND MOTHS 119 

OBSERVATIONS FOR PUPILS 

Butterflies 

A 

1. Make a list of butterflies that you know by sight. If you have 
access to the Butterfly Book or Comstock's How to know the Butterflies, 
you can identify those you see. 

2. Keep the caterpillars of some butterflies in a vivarium to see their 
changes. You can probably find some one of these : the Cabbage 
Worm, Orange-dog, Monarch Butterfly caterpillar on milkweed, Black 
Swallow-tail caterpillar on parsley, celery, or parsnip plants or the 
Mourning Cloak Butterfly caterpillars on willow, poplars, and elm. 

3. Read some of the chapters on Butterflies in Dickerson's Moths 
a?ui Butterflies ; also such of the following as you have access to : — 

American Insects, pages 446-454. Nature Biographies, pages 1-10, 11-21, 71-88. 
Stories of Insect Life, First Series, pages 12-17, 22-27, 37-40. 

B 

1. Write or tell the story of The Life of a Butterfly. Follow some 
such outline as this : — 

The laying of the egg. 
The hatching of the larva. 
The growth of the larva. 
The change to the chrysalis. 
The change to the butterfly. 
The habits of the butterfly. 

If the story is written, illustrate it by some sketches of the life stages. 

Sphinx Moths 

1. Late in summer or early in autumn one can generally find larvae 
of Sphinx Moths by a little searching of these plants : Tomato, grape, 
woodbine, or Virginia creeper, purslane, and various trees and shrubs. 

2. When a Sphinx larva is found, keep it in a vivarium with two 
inches of earth in the bottom. Feed it regularly and keep the vivarium 
clean. When it is full grown, it will probably enter the soil to pupate. 
Then put the vivarium away in a cool cellar till spring. 

3. Read these accounts of Sphinx life histories : — 

American Insects, pages 431-439. Moths and Butterflies, pages 224-242. 
Stories of Insect Life, Second Series, pages 38-45, 56-62. 



120 FARM FRIENDS AND FARM FOES 

Bombycine Moths 

i. In winter or early spring hunt for cocoons of the giant silkworms 
— Cecropia, Promethea, Polyphemus, and other large moths. When 
found, keep in a cool place until April or May, then bring into the 
schoolroom to see the moths emerge. 

Read the chapters on these moths in Dickerson's Moths and Butter- 
flies. 

2. In spring you can easily find nests of the Tent Caterpillar. Bring 
in a few larvae and rear in a vivarium. 

Read Nature Biographies, pages 22-34. 

3. In autumn you can generally find nests of the Fall Web-worm and 
easily rear a few of the larvae. 

Other Insects 

1. If you do not find Cutworms in your garden, you can probably 
find them under boards along fences or roadsides. Keep a few in a 
vivarium, feeding them leaves of clover, and see if you can rear them 
successfully. 

2. If the Boll worm, Corn Worm, or Tomato Fruit Worm occur in 
your region, see if you can find and rear some of the larvae. 

3. Late in autumn get some nearly full-grown Codling Moth larvae in 
apples, place in a vivarium, and see if you can get them to spin cocoons. 
Keep these to see if you can get the moths from them. 

4. Make an estimate of the percentage of apples injured by the 
Codling Moth in some orchard. Is the injury less in orchards sprayed 
in spring than in those not sprayed ? 

5. A little searching of the leaves of trees and shrubs at almost any 
time in summer will reveal examples of leaf rollers at work. One 
species is common in the leaves of cultivated strawberries. Another 
conspicuous one is the Wild Cherry Tent-maker. Rear some of the 
larvae into moths. A few small caterpillars can be easily reared in a 
covered jelly glass or a glass fruit-jar. 

6. Examine the leaves of apple and other trees for leaf miners. They 
are generally abundant in summer and early autumn. Break off a twig 
with infested leaves and put it in a bottle of water to keep the larvae alive 
until they change to pupae. Then put the leaf in a jelly glass or other 
suitable receptacle, covering with cheesecloth held in place by a rubber 
band. 



THE BUTTERFLIES AND MOTHS 



121 



7. Examine peach trees and peach fruits for the Peach-twig Moths. 
See if you can rear the moths. 

Read such of these references as your teacher may request : — 

The Brown-tail Moth and How to Control It, Farmers' Bulletin 264. The 
Gypsy Moth and How to Control it, Farmers' Bulletin 275. The Cotton Bollworm, 
Farmers' Bulletin 290. Insects Affecting the Cotton Plant, Farmers' Bulletin 47. 
The Imported Cabbage Worm, U. S. Bureau of Entomology, Circular 60. The 
Peach-tree Borer, U. S. Bureau of Entomology, Circular 54. 




Winter Nest of Brown-tail Moth 



CHAPTER IX 



The Two-winged Flies 

So far as numbers of individuals are concerned, the 
Two-winged Flies of the order Diptera are among the most 

abundant of all 
insects. These 
are distinguished 
by the fact that 
there is but one 
pair of wings, al- 
though in most 
species there is 
a pair of curious 
little projections 
called halteres 
or "balancers" 
which represent 
the second pair 
of wings. The 
flies have com- 
plete transformations, and in the larval state commonly ex- 
ist as footless maggots. The mouth parts are formed for 
sucking, although there are often special modifications for 
biting, in connection with the sucking apparatus. 

Fortunately, there are comparatively few species of Dip- 
tera that are destructive to cultivated crops. Among these 
few, however, are some of the most troublesome of all in- 
jurious insects, such as the Hessian Fly, the Apple Maggot, 

122 




THE TWO-WINGED FLIES 123 

the Pear Midge, the Clover-seed Midge and certain 
other pests. 

Gall Gnats 

The Hessian Fly belongs to the family of Gall Gnats 
(Cecidomyiidae). These are mosquito-like flies which live 
in the larval state upon the growing tissues of plants, 
commonly causing an abnormal swelling, which is called a 
gall. In the case of the Hessian Fly, the adult insect is a 
small creature with smoky brown wings, which appears in 
the wheat fields in autumn soon after 
the young plants are up. It deposits 
eggs upon the leaves, generally a little 
above the joints. These eggs shortly 
hatch into very small maggots that 
work their way down to the joints and 
into the space between the sheath and 
the main stalk. Here they remain 
and gradually absorb the sap of the 
plant. They grow rather slowly, and hessian fly 

their presence causes a slight swelling Magnified 

of the surrounding tissues and prevents 
the normal growth of the young wheat plant. After some 
weeks, they become full grown in this larval stage, and now 
change to what is called the flaxseed condition. To bring 
about this change the outer skin of the larva separates from 
the skin beneath and gradually hardens into a brown pro- 
tective covering. This covering, which looks like a flax- 
seed, is commonly said to be the puparium. It corresponds 
in a way to the cocoon of a moth in that it serves as a pro- 
tection to the insect inside, although its method of formation 
is entirely distinct from that by which a cocoon is formed. 

The larvae remain within these flaxseeds throughout 




124 FARM FRIENDS AND FARM FOES 

the winter. In the spring, still inside, they change to pu- 
pae, and a little later change again to adult Hessian Flies. 
These adults lay eggs for another generation of larvae that 
attack the wheat in the spring and cause much of it to be 
so dwarfed and weakened that the crop is seriously injured. 
As a rule, this brood of flies seems not to become mature 
until the latter part of the season. 

In the case of an insect so minute and so protected 
during its earlier stages as the Hessian Fly, many insecti- 
cidal methods of controlling it are useless. Consequently, 
farmers must resort to agricultural methods if they would 
prevent damage by it. One of the most successful of 
these methods is that of planting narrow strips of wheat 
early in the fall, to attract the flies to lay their eggs, in 
order that the main crop of wheat planted later may escape 
infestation. The early trap crop may then be plowed un- 
der, so that the eggs and larvae present will be destroyed. 

Another insect belonging to this same family and also 
attacking the wheat is called the Wheat Midge. The 
larvae in this case are found in the heads of grain rather 
than in the stalks, and the damage they do is in the de- 
struction or dwarfing of the kernels of wheat. In recent 
years this insect seems to have done comparatively little 
damage. 

Closely related, both in structure and habits, to the 
Wheat Midge is a tiny fly called the Clover-seed Midge. 
The flies lay their eggs in the blossom heads of clover, 
and the eggs hatch into larvae that develop at the expense 
of the young seeds, often causing a serious lessening of 
the crop where clover is grown for seed. The injury to 
hay crops, however, is very slight. 

The Pear Midge is the most destructive insect of this 
family that attacks fruit. The eggs are laid in the flower 



THE TWO-WINGED FLIES 



J 25 



buds and hatch into larvae that attack the seed cavities of 
the young pears, sometimes doing serious damage. When 
fully developed in the larval state, they drop to the ground 
where they change to pupae, and emerge soon after as 
adult flies. Plowing during the latter part of June and fer- 
tilizing with a heavy dressing of 
some potash fertilizer is helpful in 
destroying the larvae and pupae. 




APPLE 
MAGGOT 

MAGNIFIED 



LARVA 




Crane Flies 

The Crane Flies (Tipulidae) are 
among the largestof the Two-winged 
Flies. These insects look like gi- 
gantic mosquitoes and may be seen 
throughout the summer in pastures 
and meadows, as wellasabout houses. 
In their larval stages some of the 
commoner Crane Flies feed upon 
decaying vegetation and occasionally upon grass roots, 
although they are very seldom destructive in America. 
These flies show very well the peculiar balancers that rep- 
resent the second pair of wings. 

Fruit Maggots 

Comparatively few Two-winged Flies are injurious to 
fruit crops. One of the most destructive of these is the 
Apple Maggot or Railroad Worm, a pest that is often very 
troublesome in orchards. The adult fly deposits eggs be- 
neath the skins of young apples during the summer. Each 
of these eggs soon hatches into a small footless maggot 
that tunnels through the fruit in all directions. It continues 
the work for five or six weeks, by which time the apple is 
pretty well " railroaded " and ruined for cooking or eating 



126 



FARM FRIENDS AND FARM FOES 




CHANNELS OF 
APPLE MAGGOT 



purposes. The injured fruit is likely to fall to the ground. 
Then the maggot leaves it and finds shelter in the soil or 
in the rubbish at its surface. Here it changes to a pupa, 

and remains until the following sea- 
son when it emerges as an adult fly. 
Thus there is but one brood each 
year. 

Unfortunately the injuries of this 
insect cannot be prevented by spray- 
ing. The eggs are deposited beneath 
the skin of the fruit out of the reach 
of insecticides. The best method of 
checking its increase is that of picking 
up or feeding to stock, the fallen apples, so that the worms 
will be destroyed before they go into the ground. This is 
another insect that indicates the necessity of cooperation 
in agricultural methods. 

A closely related insect, which has done a great deal of 
damage in Mexico, is the Orange Maggot or Orange Fruit 
Fly. This attacks oranges in very much the same way that 
the Apple Maggot attacks apples. When introduced into 
an orange-growing locality, it is likely to become a serious 
pest. The fact that there was constant danger of its intro- 
duction into the orange- growing regions of California has 
caused much discussion among horticulturists. It is one of 
those pests for which fruit growers should be constantly on 
the watch, although, of course, there is no danger of dam- 
age from it in regions where the citrous fruits are not 
grown. 



Root Maggots 

There are a number of destructive species of flies be- 
longing to the Root-maggot group (Anthomyiinae). In 



THE TWO-WINGED FLIES 



127 



the adult state, these flies bear a general resemblance to 
the familiar house fly, although commonly they are some- 
what smaller and are easily distinguished by experts. The 
Cabbage Maggot, which is also known as the Radish Maggot, 
and the Turnip Maggot, is a good example of these insects. 
The adult flies appear in the cabbage fields when the plants 
are set out, and deposit their 
small white eggs about the 
base of the stalks. A few 
days later these eggs hatch 
into tiny, whitish, footless 
maggots that attack with 
their rasping mouth parts the 
outer tissues of the roots. 
They continue to feed and 
grow for three or four weeks, 
commonly causing the death 
of the plant on account of 
the destruction of the sec- 
ondary roots or of the girdling of the primary root. By 
the end of this period they become full-grown as larvae 
and change to pupae. 

This process of changing to the pupa state in a large 
proportion of the two-winged flies differs from that of most 
other insects. The insects are unable to spin cocoons, but 
they get the protection of an outward covering in this way : 
The skin, which in most insects is cast off when the larva 
changes to a pupa, in these maggots gradually hardens and 
becomes brownish in color. It does not split open any- 
where, so that it forms a covering to the insect, inside which 
the latter becomes a pupa after this outer skin, which is 
now called the puparium, has hardened. It remains within 
this puparium about a fortnight when it again changes into 




i 2 8 FARM FRIENDS AND FARM FOES 

an adult fly that breaks through the outer shell and emerges 
to the sunlight. The formation of the puparium takes 
place in the soil an inch or less below the surface. 

As the common names already mentioned indicate, this 
little pest is by no means confined to cabbage ; it attacks 
radishes and turnips, as well as a variety of wild plants be- 
longing to the mustard family. There are several broods 
each year. The insects commonly pass the winter as 
adult flies, although a certain proportion of them hiber- 
nate also in the puparia. 

The Cabbage Maggot has been one of the most trouble- 
some insects that the gardener has to fight. It is often 
very destructive in seed beds where the young cabbages 
for late planting are being grown. Recent experiments 
have shown that the best way of preventing this injury is 
to surround the seed beds with a broad frame twelve inches 
high, tacking cheesecloth over the frame. If the frame is 
so tight that no flies can enter, the seedlings will grow 
rapidly and be free from injury not only by these maggots, 
but also by the flea beetles which are often very destructive 
to such seedlings. When the plants are large enough to 
set out, the cloth should be removed and full exposure to 
the sun be given for at least a week. This is to harden 
the seedlings so that they may be transplanted successfully. 

The Onion Maggot is another vexatious insect belong- 
ing to this family, which is very similar to the Cabbage 
Maggot in its appearance, habits, and life history. It 
attacks onions, especially the young plants, and in many 
regions is the most destructive enemy of this crop. 

Another group of insects belonging to this same family 
attacks the leaves of cultivated crops instead of the roots. 
The adult flies deposit their whitish eggs upon the surface 
of the leaves of beets, spinach, and other succulent plants, 



THE TWO-WINGED FLIES 129 

These eggs very soon hatch into small maggots that bur- 
row through the outer skin of the leaf and begin to de- 
velop as miners of the interior tissue. They thus become 
true leaf miners, and their presence is soon shown by the 
difference in the color of the surface of the leaf. By 
holding such a leaf up to the light, the maggot inside can 
generally be seen. These larvae continue to develop 
within the leaf for a few weeks before they become full 
grown, and by this time a single larva will have injured 
a large portion of a leaf. When full grown they burrow 
through the outer skin and drop to the ground, where they 
change to pupae slightly below the surface. A little later 
they again change to adult flies. There appear to be sev- 
eral broods each year. 

As is the case with the root maggots, these leaf-mining 
species are by no means confined to cultivated crops. They 
may very commonly be found at work upon wild plants, such 
as the white pigweed or some of the commoner docks. 

OBSERVATIONS FOR PUPILS 
Hessian Fly 

1. If you live in a wheat-growing region, learn what you can about 
local damage by the Hessian Fly. If not now injurious, ask your farmer 
friends if it has been in the past. 

2. Examine wheat fields to see if you find injured plants. If so, look 
for the larvae or " flaxseeds " of this insect. 

3. If found, place the flaxseeds in a glass dish to see if you can rear 
the flies. 

4. Read the account of the Hessian Fly in Circular 70, Bureau of 
Entomology, U. S. Department of Agriculture. 

Apple Maggot 

1 . If you live in an apple region, determine whether this insect is pres- 
ent. Examine windfalls of early varieties to see if the characteristic bur- 
rows in the pulp are present. 



130 FARM FRIENDS AND FARM FOES 

2. If the pest is at work, gather some injured apples, and place in a 
box with an inch or two of soil in the bottom. The larvae will probably 
enter the soil, and you will be able to rear the flies. 

Root Maggots 

1. What crops in your region are injured by root maggots ? 

2. Get some of the maggots from roots of radish, turnip, cabbage, or 
onion. Keep in moist earth and see the change to puparia and later to 
flies. 

3. Try to find eggs, larvae, and puparia about the roots of injured 
plants. 

Leaf-mining Maggots 

1 . Examine the leaves of beets, spinach, dock, and pigweed to find 
discolored areas. If made by the leaf miners, the larvae may readily be 
seen by holding the leaf up to the light or by opening the mine. 

2. Place some of the leaves that have larvae of good size in a bottle 
of water. Set in a vivarium with earth in the bottom. The larvae will 
probably pupate in the earth and later change to flies. 

The Story 

Tell or write the life story of one of these injurious flies that you know- 
most about. Illustrate by drawings on blackboard or paper. Perhaps 
this outline will help you : — 

Size, color, and appearance of the fly. 

When and where the flies are found. 

When and where the eggs are laid. 

Size and color of the eggs. 

How soon the eggs hatch. 

What the larvae feed on. 

How long the larvae live. 

Where the larvae change to pupae. 

How long before the pupae change to flies. 



CHAPTER X 




The Beetles : Order Coleoptera 

The great order of sheath-winged insects to which the 
beetles belong is one of the largest and most important 
groups of insects. 
Most of its mem- 
bers have har- 
dened wing cov- 
ers over the true 

wings, and the ^^ Pupa 

whole outer sur- 
face of the body 
is hardened in 
a characteristic 
manner. The 
larvae are grubs 
that vary greatly 
in form and hab- 
its, and the pupa 
is a quiet stage in 
which the insect does not eat or move about. 

The feeding habits of the adult beetles are exceedingly 

varied ; many feed upon plant tissues ; many others upon 

animals, alive or dead. Among the plant-feeding groups 

are some of the most troublesome, injurious insects, while 

among the animal-feeding forms are some very beneficial 

insects. 

131 




LARVa 



WHITE GRUB 

or 
MAY BEETLE 

Eqq 






Adult 



132 



FARM FRIENDS AND FARM FOES 




Lamellicorn 
Beetle 



Lamellicorn Beetles 

Only a few of the great number of beetle families can 

be considered in these pages. One of the most important 

of these is the great group of Lamellicorn Beetles (Scara- 

baeids). These have curious enlargements on the ends of 
the feelers or antennae, each swollen part 
consisting of a number of thin plates rest- 
ing upon one another. The May Beetle is 
a typical example of this group. 

In both its adult and its larval condition, 
the May Beetle or June Bug is only too 
familiar to most people. From the advent 
of the first warm days in spring until sum- 
mer is well along, the brown beetles are 
likely to be seen flying about trees or lights 

or crawling along the surface of the ground. These beetles 

feed freely upon the leaves of a great variety of fruit 

and shade trees, sometimes doing much injury in this way. 

They deposit their eggs about the bases of grass stems, 

md the eggs soon hatch 

into small larvae that feed 

upon the roots of grasses 

and gradually develop 

into the well-known white 

grubs, which are almost 

always to be found in 

abundance when grass 

lands are plowed. It is 

believed that these white 

grubs require at least 

three years to complete their development, becoming large 

toward the end of this period and able to destroy the roots 




Potato injured by White Grub 
Reduced 



THE BEETLES: ORDER COLEOPTERA 



33 



of many plants. They finally change to pupae in earthen 
cells and generally change again to adult beetles in late 
summer or autumn. The beetles remain in the soil until 
the following spring. 

The white grubs have many enemies among birds and 
wild animals, such as foxes and skunks. These natural 
enemies are the most potent means of keeping them in 
check in regions where the grubs become destructive. 
The killing of the adult beetles by attracting to lights or 
collecting in other ways will often become necessary. 
This is a case, however, where concerted action by all the 
farmers of the community is exceedingly desirable. 

Another vexatious member of this great family of bee- 
tles is the so-called Rose Chafer or Rose Bug. This is 
one of the most destructive enemies of fruits. The 
brown beetles appear in vast swarms early in sum- 
mer, when the wild roses are in blossom. They 
feed upon the leaves and flowers of a great vari- 
ety of fruit and ornamental plants, such as apples, Rose 
pears, plums, peaches, roses, raspberries, straw- 
berries, blackberries, and grapes. They often do serious 
damage to the grape crop by eating the blossoms. The 
beetles remain active two or three weeks. During the 
latter part of this period, the eggs for a new brood are 
laid in the ground. The insect chooses for this purpose 
open fields and meadows having a sandy soil. About a 
fortnight later, the eggs hatch into small grubs that feed 
upon roots of grasses. These grubs become full grown, or 
nearly so, during the summer and early autumn. On the 
approach of winter, they burrow deeper, and the following 
spring again work their way upward near the surface. 
Here in earthen cells they change to pupae, and emerge a 
month later as fully developed beetles. 




134 



FARM FRIENDS AND FARM FOES 



This is a difficult pest to contend against. The most 
effective method as yet employed is the laborious one of 
picking the beetles by hand and destroying them. 

Click Beetles 

Every farmer's boy is familiar with the slender, yellow 
Wireworms so commonly found when grass lands are 
plowed. These insects feed upon the roots of grasses and 
grains. They often become seriously destructive to crops 
planted upon ground that has been in 
sod for several years. When fully de- 
veloped in their larval stage, these Wire- 
worms change to pupae within oval cells 
in the soil and a few weeks later change 
again into adult Click Beetles or Elaters. 
They usually remain, however, within 
the cells until the following spring, the 
tissues gradually hardening until they 
become very firm and hard even for a 
beetle. Then the adults come forth and 
fly freely about, often visiting various 
flowers from which they lap up the nectar. These Elaters 
are often called Snapping Beetles from the fact that when 
placed upon their backs, they snap upward, apparently in 
an effort to regain the crawling position. It is supposed 
that the eggs are laid about the roots of grasses. 

The Wireworms are very difficult to destroy by any form 
of insecticides. The most desirable method of checking 
their increase seems to be that of fall plowing, which breaks 
up the pupal cells and exposes the beetles to destruction 
by weather conditions through the winter. 




Eyed Elate r 



THE BEETLES: ORDER COLEOPTERA 



J 35 



Leaf Beetles 




Leaf 
Beetle 



One of the most generally destructive families of beetles 
is that of the Leaf Beetles (Chrysomelidae). As a rule, these 
are elongated or roundish beetles, having jaws especially 
adapted for feeding upon leaves. Their larvae, for the 
most part, are short, thick grubs, with well-de- 
veloped thoracic legs. They feed in both the 
larval and adult states upon a great variety of 
wild and cultivated plants, and often become seri- 
ously destructive to the latter. 

No member of this great family is so generally 
and unfavorably known as the Colorado Potato Beetle. 
Originally a native of the Rocky Mountain region, where it 
fed upon a wild species of Solanum, — the genus to which 
the common potato belongs, — it started eastward as soon 
as the settlers' garden patches connected its home with the 
Atlantic states by means of a practically continuous potato 
field. Then it boarded transatlantic steamships and stole 

a passage to Europe, 
where it gained a de- 
cided foothold before re- 
ceiving the attention it 
deserved. 

The various stages 
of the Colorado Potato 
Beetle are shown in 
the accompanying pic- 
tures. The brown-striped 
beetles deposit the or- 
ange-colored eggs in masses upon the leaves. These eggs 
shortly hatch into the curious brown grublike larvae, which 
feed upon the tissues of the leaves and cast their skins 




Adult 



COLORADO POTATO-BEETLE 



136 FARM FRIENDS AND FARM FOES 

occasionally as they increase in size. In three or four 
weeks, they become full-grown as larvae. Then they make 
their way into the soil and change to pupae. Ten days 
later they change again to adult beetles. The number of 
broods varies with the latitude, there being from two to 
four each year. The eggs are eaten by lady-bird beetles, 
and the adults are devoured by certain birds, notably the 
grosbeaks and the bobwhite. Both larvae and adults are 
readily killed by spraying or dusting the potato vines with 
arsenical poisons. 

Another leaf beetle that is very often destructive is the 
Asparagus Beetle. This is one of those numerous pests 
that have been introduced into America from Europe. It 
is not yet generally distributed, but is constantly being in- 
troduced into new localities where asparagus is grown. 
The adult beetle is rather slender, less than half an inch 
long, and is easily recognized by the brilliant combination 
of black marked with red or yellow. When such a beetle 
is found feeding upon asparagus, it is pretty certain to be 
this Asparagus Beetle. If there are twelve spots, however, 
it is probably the less common Twelve-spotted Aspar- 
agus Beetle, which has also been lately introduced from 
Europe. 

The eggs of the common Asparagus Beetle are deposited 
upon the leaves and stems of the plants, and soon hatch 
into small grublike larvae that feed freely upon the leaves, 
often doing great damage to young plantations. These 
larvae pupate in the ground and soon emerge again as 
adult beetles. 

Various methods of checking Asparagus Beetles have 
been found successful on young plantations. Dusting the 
vines when they are wet with dew with fresh, dry air-slaked 
lime has been found to kill the larvae. On older planta- 



THE BEETLES: ORDER COLEOPTERA 137 

tions, which are being cut over, the leaving of a few stalks 
as trap plants to attract the adult beetles when they lay 
their eggs has been found effective. These trap plants, 
of course, are to be destroyed often enough to prevent the 
eggs from hatching. 

A much more familiar and widely distributed leaf beetle 
is the common Striped Cucumber Beetle, which is found 
practically everywhere that cucumbers, melons, squashes, 
or related plants are grown. These insects pass the 
winter as adults under such shelter as they may find, and 
in spring feed ravenously upon the young cucumber or 
other plants. They also deposit their eggs about the 
roots of these plants, and the eggs shortly hatch into 
slender larvae that feed upon the roots. In this way, the 
beetles not only threaten the crop in their adult state, but 
they often do a more serious, though less recognized, 
damage in their larval state. These are among the most 
difficult of all pests to keep in check. A few hills may be 
covered with netting or cloth. The liberal use of refuse 
tobacco powder is generally also an efficient protection. 
The complete destruction of all squash, cucumber, melon, 
and pumpkin vines as soon as the crop is gathered is a 
very desirable preventive measure. If these are left, the 
adult beetles find abundant food up to the time they go 
into their hibernating quarters, and consequently are in 
better condition to survive the winter. 

A closely related insect, which at times has. been ex- 
ceedingly destructive, is the Northern Corn Rootworm. 
This is a small beetle, about the size of the Cucumber 
Beetle, but of a uniform pale green color. In the larval 
state it feeds upon the roots of corn and so weakens the 
plants that the development of the crop is greatly 
checked. The larvae change to the pupa state and 



138 FARM FRIENDS AND FARM FOES 

emerge as beetles during the later part of summer or 
early in autumn. 

These beetles then deposit eggs in the same fields in 
which they were developed and the eggs remain unhatched 
until the following spring. If corn is then planted, the 
larvae feed again upon the roots and repeat the injury of 
the season before, but if the field is planted to some other 
crop upon which the larvae are unable to develop, the in- 
sects will die and the damage will be prevented. Conse- 
quently this Corn Rootworm has been a blessing in disguise, 
for it has compelled those farmers who were depleting the 
fertility of their land by a constant succession of corn 
crops, to adopt a system of rotation. The discovery of 
the life history of the Northern Corn Rootworm and the 
pointing out of the fact that its injuries may be prevented 
by the rotation of crops is one of the most notable ex- 
amples of the benefits to be derived from scientific ento- 
mology. The credit for it is due to Dr. S. A. Forbes, the 
state entomologist of Illinois. 

The insect known in many of the Northern states as 
the Twelve-spotted Cucumber Beetle, is also known in the 
South as the Southern Corn Rootworm. Throughout its 
range, it feeds as an adult upon succulent leaves, and 
probably develops as a larva upon a considerable variety 
of plant roots. In Kentucky and some other Southern 
states it causes much damage to corn crops. Its Southern 
life history is briefly this : The adult beetles hibernate at 
the surface of the soil or just below, in fields of clover, al- 
falfa, and other crops. They come forth early in spring, 
and as soon as the young corn plants are well started, they 
deposit their eggs about the roots. The eggs soort hatch 
into larvae that become full grown early in summer, chang- 
ing to pupae and soon again into adults which appear 



THE BEETLES: ORDER COLEOPTERA 139 

about midsummer. In a short time, these lay eggs for a 
second brood of larvae that develop into adult beetles in 
autumn. These beetles hibernate until the following 
spring. There are thus two broods of larvae each season. 
The fact that this Southern Corn Rootworm hibernates 
in the adult condition and that the beetles can fly freely 
from place to place, shows at once that this pest cannot be 
checked by the simple method of rotation that serves the 
purpose in the case of the Northern Corn Rootworm. 
Rotation of crops will be helpful, especially if care is 
taken not to plant to corn those fields to which the adult 
beetles were attracted the previous autumn by an abun- 
dant supply of succulent food. 

Flea Beetles 

There are several species of Flea Beetles which also be- 
long to this leaf-beetle family. Some of the larger Flea 
Beetles have a life history similar to that of the Asparagus 
Beetle and the Colorado Potato Beetle, both larvae and 
adults feeding upon the foliage of the food plants. The 
Grape Flea Beetle is an excellent example of 
these insects. It often becomes a destructive 
pest in vineyard regions. 

The smaller Flea Beetles, however, are more 
universally distributed and affect a great vari- 
ety of cultivated crops. These are tiny beetles f 
which are able to jump great distances when Magnified 
disturbed, and which are only too commonly 
found upon potato, tomato, cabbage, and other garden 
plants. They not only do decided damage by eating out 
the surface of the foliage, but they afford an easy ingress 
for the germinating spores of many kinds of fungous dis- 
eases. In their larval state, some, at least, of these smaller 




140 



FARM FRIENDS AND FARM FOES 



Flea Beetles live as miners in the leaves and stems of va- 
rious plants. Spraying with Bordeaux mixture is one of 
the best methods of preventing their injuries. 

Long-horn Beetles 

The so-called Long-horn Beetles (Cerambycidae) form 
one of the most important groups of the order. The adults 

have cylindrical bodies, frequent- 
ly of large size, with feelers or an- 
tennae generally as long as the 
bodies or longer. These beetles 
deposit their eggs upon the bark 
or wood of a great variety of trees 
and shrubs, and the eggs hatch 
into footless grubs that burrow 
into the bark or wood of the host 
plant. Some of the most destruc- 
tive fruit-tree pests belong to this 
family, a notable example being 
the Round-headed Apple-tree 
Borer, which is often very injurious in apple orchards. 

The Locust Borer is one of the most abundant as well 
as most beautiful of the beetles belonging to this family. 
It is attractively colored, being brown or 
black, marked and striped with lines of 
light yellow. This beetle is very abun- 
dant in late summer and early autumn 
upon the flowers of goldenrod, which it 
visits in search of pollen. The life his- 
tory briefly summarized is this : The 
beetles found in August or September 

deposit their egsrs one at a time in the 

i && Locust Borer 

crevices of the bark of the common or beetle 





Round-headed Apple-tree 

Borers 

Beetle and Pupa 




THE BEETLES: ORDER COLEOPTERA 141 

black locust trees. In about ten days these eggs hatch 
into tiny larvae that excavate slight cells in the bark ; they 
remain in these cells throughout the winter. Soon after 
the sap begins to flow the following spring, the larvae be- 
come active and begin to burrow through the bark into the 
wood. The burrows that they make are commonly not 
very long and are enlarged as the insects increase in size. 
The larvae become full grown in a few months, and change 
to pupae within their burrows about midsummer. A little 
later they change again to adult beetles that come forth to 
feed upon goldenrod flowers and deposit eggs for another 
generation of borers. 

The characteristic larvae of various wood-borjng beetles 
are very often to be seen when firewood is split up, dropping 
out of the cylindrical chambers they have burrowed in the 
wood. They may also frequently be found beneath the 
bark of fallen trees or in the partially decayed wood of 
dead stumps. Some species are much more destructive 
than others, but in general their life histories are quite simi- 
lar. The Pine Sawyer is a large species that breeds in 
dead pine trees and often causes losses of millions of 
dollars in a single year. The Oak Twig Pruner is another 
widespread pest ; it may commonly be found in fallen twigs 
under oak trees. 

CURCULIOS AND OTHER SNOUT BEETLES 

Most farmers' boys know how difficult it is to grow 
plums. From the time the fruit is half grown until it is 
ripe it continues to fall to the ground, and when examined 
is found to be wormy and unfit to eat. This worminess 
is generally due to the insect known as the Plum Curculio, 
a small, hard-shelled, brownish beetle, which appears among 
the plum trees in spring. It gnaws holes in the leaves, 



142 



FARM FRIENDS AND FARM FOES 




-Food Puncture 
Larva----— 

£gq Puncture 

PLUM 
CURCULIO 




the flowers, and the green plums to satisfy its hunger. ' The 
females also cut crescent-shaped holes in the skin of the 
young fruits and deposit an Qgg beneath each of the cres- 
cent marks. In from 
three to seven days these 
eggs hatch into little 
grubs that feed upon the 
pulp of the fruit, gradu- 
ally working toward the 
pit. They become full- 
grown in two or three 
weeks. The infested 
plums by this time are 
so injured that they generally fall to the ground. Then 
the larvae leave the fruit, and burrow into the soil about an 
inch, where they change to pupae. Three or four weeks 
later, they change again and come forth as perfect beetles. 
There is but one brood of the worms 
each season. The adult beetles hiber- 
nate under such shelter as they can find 
at the surface of the soil. 

The Plum Curculio is by no means an 
unmixed evil. In many localities it per- 
forms an essential service by thinning 
the plums, thus saving the fruit grower 
much expense. Besides plums, it attacks 
peaches, cherries, apricots, nectarines, 
apples, and pears. In the case of the 
last two a large proportion of the larvae 
appear to be unable to develop in the 
green fruit, but the injuries by the adult beetles often cause 
the fruits to be dwarfed and gnarly. 

There are several natural enemies of the Plum Curculio. 




THE BEETLES: ORDER COLEOPTERA 



J 43 




One of the most efficient of these is the tiny fly that depos- 
its its eggs in the eggs of the Curculio. The fly eggs hatch 
into maggots that destroy the Curculio eggs and mature in 
a few days into other flies like the parent parasites. Conse- 
quently several generations of these Qgg parasites may 
follow one another through the season. 
There are also other parasites that attack 
the Curculio larvae. The fluctuations in 
the abundance of the Curculios from sea- 
son to season is probably due chiefly to 
these parasitic enemies. 

It has been found that even in large 
orchards the injuries of the Plum Cur- 
culio may be prevented to a great ex- 
tent by spraying the trees with arsenical 
poisons, beginning just after the blossoms 
have fallen. The adult beetles feeding 
upon the leaves and young fruit are thus 
poisoned. For a few trees this method is not always so 
successful, and it is necessary to adopt the jarring device. 
When a branch upon which the adult beetles are resting is 
shaken, the insects fall to the ground, remaining quiet for 
some time afterward. By holding sheets stretched upon 
wooden frames under the trees and then shaking the latter, 
the beetles may be collected in numbers. It is also often 
advisable to supplement the spraying, even in large 
orchards, by the jarring process. The destruction of the 
plums as fast as they fall and the cultivation of the soil 
beneath the trees during the summer are also helpful 
measures. 

A group of Snout Beetles that at times has proved 
very destructive in the great corn-growing regions of the 
Central West, is that of the Billbugs. These are compara- 



INJUREO BY 
CURCULIO 



144 



FARM FRIENDS AND FARM FOES 



tively large insects, having hard bodies with long snouts, on 
the ends of which are well-developed jaws by means of 
which they can burrow through young cornstalks very 
quickly. The adult beetles feed upon the tissues of these 
stalks, greatly weakening the plant when they burrow 
through it. In the case of a typical species, the insect 
hibernates in the adult state, and attacks the young corn 
soon after it comes up. The eggs are laid in early sum- 
mer, commonly about the bulbs of timothy and perhaps 
other plants, and the larvae burrow into these bulbs and there 
develop. They grow rapidly and become mature beetles 
late in summer or early in autumn. 

Some of the best-known species of Billbugs develop as 
larvae in sedges or rushes of various kinds. Practically all 
of them appear to breed chiefly on low lands where sedges 
are likely to abound. The cornfields often injured are 
those upon or near such lands. Fall plowing is an efficient 
preventive of injury by these pests. 

Cotton Boll Weevil 

The Cotton Boll Weevil has attracted more attention 
during recent years than almost any other destructive 

insect. Migrating into 
Texas from Mexico about 
the year 1890, this pest 
has gradually spread to- 
ward the north and east 
and threatens to become 
destructive almost every- 
where that cotton is 
grown. Within about a 
dozen years of its intro- 
duction, when it was still 




ADULT 




LARVA 



MEXICAN 

COTTON BOLL 

WEEVIL 

TGG 





PUPA 



THE BEETLES: ORDER COLEOPTERA 



145 



largely confined within the borders of Texas, the loss to 
the cotton crop in one year due to this insect was esti- 
mated at $15,000,000 by Dr. L. O. Howard, entomologist 
of the United States Department of Agriculture. The 
possible annual loss to the cotton planters of the South 
in case the pest should be- 
come generally distributed, 
has been estimated at 
$250,000,000. Conse- 
quently it is not strange 
that this insect has received 
a great deal of attention 
from the national and state 
governments, and that 
strenuous efforts are being 
made to destroy it where 
it now exists, and to pre- 
vent its introduction into 
new localities. 

Briefly stated, the life 
history of the Boll Weevil is this : The adult snout beetles 
pass the winter in a great variety of shelters, in or near 
the cotton fields. In spring they come forth from their 
hibernating quarters and attack the young plants, feeding 
upon the buds, in which they make small round holes. In 
some of these holes are deposited eggs that soon hatch 
into whitish, footless grubs that feed upon the interior of 
the buds, destroying the blossoms and thus greatly injuring 
the prospects of the crop. These larvae grow rapidly and 
in a few weeks become mature, so far as this stage is con- 
cerned. They then change to pupae still within the shelter 
of the bud, and a little later change to adult beetles. They 
gnaw their way out and soon deposit eggs for a second 




INFESTED COTTON SQUARE 



146 FARM FRIENDS AND FARM FOES 

brood of larvae. There are several broods during the sea- 
son, the larvae being able in the hot weather of midsummer 
to become full grown, so far as the larval stage alone is 
concerned, in one week. The later broods develop within 
the cotton bolls and thus cause a vast amount of damage. 

The Boll Weevils continue to multiply through the fall 
upon any plants that are still present in the fields, and those 
which hibernate most successfully are the ones that develop 
latest in the season. Consequently, as a result of many 
careful observations and experiments, it is pretty certainly 
established that the most effective practical remedy for the 
insect is to pull up and burn all the cotton plants present 
in the fields in autumn. This may usually be done by cut- 
ting off the roots with a plow and then at once gathering 
the plants by hand and piling them in windrows where they 
will rapidly dry out, and in about two weeks may be burned. 
The addition of a little crude oil is sometimes desirable to 
insure the complete destruction of all the stalks. In an in- 
teresting experiment conducted by the Department of Agri- 
culture, an isolated cotton-growing region of about four hun- 
dred acres was thus treated in autumn, with the result that 
the beetles were nearly all destroyed and the following season 
the amount of damage done by them was insignificant. 

Fall plowing is often a desirable procedure in cotton 
culture whether the Boll Weevils are present or not, and so 
it seems that this pest, like so many others, will bring about 
an improvement in agricultural methods. 

OBSERVATIONS FOR PUPILS 
Plum Curculio 



i . Pick up some green plums from beneath the trees. Can you find any 
of the crescent-shaped marks where the Curculios have laid their 



THE BEETLES: ORDER COLEOPTERA 147 

eggs ? Can you find any holes where the Curculios have been simply 
feeding? 

2. Cut open some of the fallen plums. Can you find eggs or larvae 
in the green pulp? Can you trace the holes made by the larvae in bur- 
rowing through the pulp? 

3. Place a few freshly fallen plums on two or three inches of garden 
soil in the bottom of a glass jar or a wooden box. A week later see if 
you can find any larvae or pupae in the soil. Leave some of them and 
see if you can rear the adult beetles. 

4. Hold a sheet or a large piece of paper under a plum tree and jar 
the limbs above. See if you can get any of the Curculios in this way. 
You may know them by their hard shells and curious snouts. Place a 
few of them under a bell glass with a branch of green plums held in a 
bottle of water. Watch the beetles eating and ovipositing. 

5. Examine peaches, cherries, apples, and pears to find similar injuries 
of the Curculios. Do you find any live Curculio larvae in green apples 
and pears? 

B 

1. Write or tell a little story with this title: The Life of the Plum 
Curculio. Follow this outline : — 

The beetle in winter. » 

The beetle in spring. 

The laying of the egg. 

The hatching of the egg. 

The growth of the larva. 

The change to the pupa. 

The change to the adult. 

Remedies for injuries by Curculios. 

2. Make some or all of these drawings : A plum showing feeding 
holes and crescent holes ; a section of an injured plum with larva in- 
side ; an apple or a peach injured by Curculios. 

3. Read Circular 73, U. S. Bureau of Entomology. 

May Beetles 

1. Have you ever seen white grubs in the soil turned over in plow- 
ing or spading ? 

2. Are these grubs more likely to be found in sod land than in that 
which has been cultivated for several years ? 



148 FARM FRIENDS AND FARM FOES 

3. Did you ever see the fully developed beetles in freshly plowed 
ground ? At what seasons are they found ? 

4. Collect some of the beetles that fly about during the evenings in 
May or June. Kill them in a cyanide bottle. Study their structure. 
How do they differ from grasshoppers ? 

5. When the beetles are thick, try putting a lantern outdoors over a 
tub of water with a bit of kerosene on top. See how many beetles are 
killed in this way. Write or tell the story of the life history of the 
May Beetle. Make some drawings to illustrate the story. 

Cotton Boll Weevil 

1. If you live in a cotton-growing region, find out whether the Boll 
Weevil is present. If so, learn how long since it first appeared in your 
locality. 

2. See what stages of the weevils you can find. 

3. Look especially in cotton fields in fall to see whether any of the 
pests are hibernating there. 

4. Learn what methods of preventing injury by weevils have been 
adopted by the cotton growers. 

5. Write a little story with this title: What I Know about Boll 
Weevils. Illustrate it with drawings. 

6. Read the account of the Cotton Boll Weevil in Farmers 1 Bulletin 



344- 



Rose Chafer 



1. At what season do you find the first Rose Chafers ? 

2. What plants do they attack most seriously in your region? 

3. Are there extensive sandy lands near, where the larvae may de- 
velop ? 

4. Why is it probable that few birds would eat these beetles ? 

Other Beetles 
Read such of the following references as your teacher directs : — 

The Corn Rootworms, Circular 54, U. S. Bureau of Entomology. The 
Clover Root-borer, Circular 67, U. S. Bureau of Entomology. The Colorado 
Potato Beetle, Circular 87, U. S. Bureau of Entomology. The Fruit-tree Bark- 
beetle, Circular 29, U. S. Bureau of Entomology. The Larger Apple-tree 
Borers, Circular 32, U. S. Bureau of Entomology. 



CHAPTER XI 

Hymenoptera : the Ants, Bees, Wasps, and Sawflies 

The ants, bees, wasps, and sawflies, with other related in- 
sects, form one of the most characteristic of all the orders. 
It is called Hymenoptera, and its members may be known by 
the fact that they pass through complete transformations, 
and that the adults generally have four more or less trans- 
parent membranous wings, of which the front pair is the 
larger. The mouth parts are formed for biting, but there 
is commonly present also a tongue by means of which the 
insects can suck or lap up liquids. In the case of the 
higher members of this order, the larvae feed upon a special 
food prepared by the adults. 

Sawflies 

As very few of the Hymenoptera feed on plant tissues, 
a comparatively limited number of injurious species are 
found in the order. Of these the most im- 
portant belong to the great family of Sawflies 
(Tenthredinidae) which are characterized by 
having an ovipositor by means of which the 
insects are able to cut holes in vegetable tis- CHERRY Saw - 

r . . r~, FLY Magnified 

sues for the insertion of their eggs. The 
eggs are commonly laid within such cavities, but sometimes 
they are deposited along the outer surface of leaf or stem. 
They soon hatch into caterpillar-like larvae, commonly 
called false caterpillars or slugs, which feed upon the foli- 
age and finally spin cocoons within which they change to 

149 




I^O 



FARM FRIENDS AND FARM FOES 



pupae, and change again later into adult sawflies. The 
sawfly larvae have three pairs of true legs and six to eight 
pairs of prolegs. Most of them have the abdomen curved 
inward in the curious way shown in the 
picture of the Willow Sawfly larva. 

The Common Currant Worm is one of 
the most familiar of the sawflies, and its 
life history fairly illustrates that of many 
related species. The small whitish glassy 
eggs are deposited in spring upon the 
principal veins of the under side of the 
lower leaves of currants and gooseberries. 
In about ten days these eggs hatch into 
small whitish grubs or larvae that eat cir- 
cular holes in the leaves. After a few 
days they cast their skins or molt — a 
process that is repeated several times dur- 
ing the next six weeks. In color they 
change from whitish to plain green, but 
soon become dotted with black, a color condition that con- 
tinues until the last molt, when they change to light green 
with a little yellow on some parts of the body. As they 
grow older the injury to the leaves increases, and in severe 
attacks the bushes are completely defoliated. 

When fully grown in the larval stage, the Currant Worms 
descend to the ground, seeking shelter beneath the leaves 
and rubbish. There they spin tough, brown, silken cocoons 
within which they change to pupae. A short time later 
they again change to four-winged flies. These come forth 
early in summer and deposit eggs for a second brood of 
larvae, most of which pass the following winter within their 
cocoons. 

The eggs of the Currant Worm, small as they are, are 




Willow Sawfly 
Larva 



ANTS, BEES, AND WASPS 151 

infested by a tiny parasite that develops in them. An ex- 
ceedingly minute fly deposits its eggs within the eggs of 
the Currant Worm — one in each. The former hatch into 
tiny footless larvae that develop at the expense of the 
material of the Currant Worm egg. Finally these larvae 
pupate and later change to tiny adult flies. 

This Currant Worm was originally a native of Europe, 
having been introduced into America many years ago. Its 
injuries may be prevented by spraying or dusting the 
bushes with hellebore when the larvae are young. It should 
not be applied when the fruit is ripening. 

In addition to the Currant Worm, there are a number 
of other insects belonging to this group. A very similar 
species feeds upon the foliage of raspberries and is called 
the Raspberry Sawfly. Another feeds upon strawberry 
leaves and is called the Strawberry Sawfly. Still an- 
other, which is an unusually large species, feeds upon 
willow and is called the Willow Sawfly. Avery character- 
istic form often injures grape leaves and is sometimes 
called the Grape Slug. 

Two similar and characteristic sawfly larvae are found 
upon pears, plums, and cherries, and upon roses. These 
have in their younger stages curious slimy skins and eat 
only the surface of the leaves, causing a characteristic and 
easily recognized injury. The presence of this slimy coat- 
ing enables one to kill them readily by applying almost any 
fine powder, such as road dust or air-slaked lime to the af- 
fected foliage. The particles will adhere to the larvae and 
eventually cause their death. 

Most of these false caterpillars are marked in colors of 
striking contrast which indicate that they have some method 
of defense from birds. They are thus examples of what 
the naturalists call warning coloration, and they seem to 



152 FARM FRIENDS AND FARM FOES 

be comparatively little injured by birds. All of them, how- 
ever, are easily destroyed by spraying with arsenical poisons 
or even with insect powder or hellebore. 

Four-winged Gallflies 

The next most important group of injurious insects be- 
longing to the Hymenoptera is that of the Gallflies (Cyni- 
pidae). There are many species of these insects which 
affect almost every sort of tree, shrub, and herbaceous 
plant, but comparatively few of them are destructive to 
cultivated crops. 

One of the most familiar of these injurious insects is the 
species that makes its home in blackberry canes, causing a 
large abnormal swelling upon the cane which is commonly 
called the pithy Blackberry Gall. The small four-winged 
Gallfly deposits its eggs in the growing stem, a large 
number of eggs being placed near together. These hatch 
into tiny larvae which bring about an abnormal growth of 
the blackberry tissues that eventually takes the form of the 
curious gall. If you cut one of these open, you are likely 
to find a great many little cells in which the larvae are 
living. They finally transform to pupae within these cells, 
and emerge later as adult flies. The cutting and burning 
of all affected stalks in winter will help to check the increase 
of these insects. 

A great many forms of Gall insects may be found at al- 
most any time upon the willows and the oaks. The familiar 
oak apples are excellent examples of the sort of abnormal 
vegetation growth caused by the Gallflies. 

Chalcid Flies 

The great family of small parasitic flies, called the Chalcid 
family, consists for the most part of insects that live in their 



ANTS, BEES, AND WASPS 153 

larval stages upon other insects. A very few, however, 
develop at the expense of vegetable tissues. The Wheat 
Jointworm, of the genus Isosoma, is the most notable ex- 
ample of the latter. The adult of this is a small fly 
which deposits its eggs in the wheat stem at or near a joint. 
The Qgg hatches into a tiny footless larva, which absorbs 
the sap of the plant, causing the tissue to harden and the 
growth of the wheat to be injured. The larva finally ma- 
tures into a pupa and again into an adult fly. When it is 
present in large numbers, it may seriously injure the 
wheat crop, but it is comparatively easily destroyed by any 
procedure that causes the destruction of the stalks contain- 
ing larvae or pupae. The burning of the wheat stubble is 
one effective remedial measure. 

OBSERVATIONS FOR PUPILS 
Imported Currant Worm 

1. In spring or summer examine the leaves of currant and gooseberry 
bushes carefully for the eggs upon the under side of the midrib and 
secondary veins. Do you suppose all the eggs on one leaf are deposited 
by one sawfly ? 

2. If you find any leaves with eggs upon them, place the leaf in a 
vivarium with the stem inserted in a bottle of water. Watch for the 
hatching of the larvae, and feed them fresh leaves from day to day. 

3. Look at the lower leaves on the currant bushes to find some with 
round holes in them. Are there any currant worms at work on such 
leaves ? 

4. Raise a few currant worms in a jelly glass or other vivarium. 
Note the changes of color from time to time. Can you find the cast 
skins after molting ? Do the caterpillars stop eating and rest before and 
after molting ? Where does the skin split open before it is cast off? 

5. Examine carefully the legs on a good-sized currant worm. Are 
they all alike ? Which are more pointed ? How many legs in all ? 
Watch the insect as it crawls, and notice how the legs are used. 

6. When the larvae spin their cocoons, notice the texture of these. 



154 



FARM FRIENDS AND FARM FOES 



Is it like the texture of a moth cocoon ? Are they water-tight ? Can 
you find any cocoons out of doors beneath infested currant bushes ? 

7. Cut open a cocoon in which the insect has pupated and find the 
pupa and the cast skin. Compare this pupa, especially in regard to the 
distinctness of the legs and other appendages with the pupa of a moth 
or butterfly. 

8. Observe how the fly escapes from the cocoon. Does it gnaw off 
a cap ? Compare it with a bee or a wasp and then with a two-winged 
fly. Study its structural characters. 

9. Give either orallv or in writing a short account of the life of the 
Currant Worm. ■ This outline may help : — 

The laying of the eggs. 
The hatching of the eggs. 
The growth of the caterpillar. 
The spinning of the cocoon. 
The change to the pupa. 
The change to the adult fly. 

10. Make these drawings : A leaf with round holes made by young 
larvae ; leaf badly eaten ; a larva, side view; a cocoon ; an adult sawfly. 

Other Insects 

Read such of the following references as your teacher may direct : — 

The joint Worm, Circular 66, U. S. Bureau of Entomology. Insect Enemies 
of Growing Wheat, Farmers' Bulletin, 132. 



CHAPTER XII 



Insecticides and their Application 

It is well known that there are two principal ways in 
which plant-feeding insects get their food. Some insects 
bite or chew the parts of the plants upon which they feed, 
while others are provided with a hollow beak that they 
push into the tissues of the plant to suck the sap. All the 
leaf-eating caterpillars are examples of the biting insects, 
while the plant lice, squash bug, and many related species 
are examples of the sucking insects. The picture below 
shows the way in which the sucking mouth parts of the 
plant louse are inserted among the cells of plant tissues. 

This essential difference in the feeding habits of insects 
must be considered when we try to kill them by the appli- 
cation of insecticides. In the case of a 
biting insect, we may hope to poison it 
by placing fine particles of arsenic in some 
form upon the leaves of the food plant. 
As the insect bites the leaves, it will be 
likely to eat some of these particles and 
be killed. But in the case of a sucking 
insect, we must use some insecticide that 
will kill by coming in contact with the 
insect itself. Such insecticides commonly 
act by reaching the interior of the insect 
through the breathing pores, or trachece, 
and so they are sometimes called tracheal poisons to dis- 
tinguish them from the ordinary internal poisons. Kero- 

i55 




Head of Aphis 

showing Sucking 

Tongue among 

Plant Cells 

Magnified 



156 



FARM FRIENDS AND FARM FOES 



sene, whale-oil soap, and pyrethrum or insect powder are 
among the most important tracheal poisons. 

Some plant-feeding larvae have such slimy skins that they 
are readily killed by dusting with powdered air-slaked lime, 
or ashes. The "slugs" on pear, cherry, and rose leaves 
are examples of these. 

Internal Poisons 

The poisons most commonly used against biting insects 
are certain chemical compounds composed in part of ar- 
senic. Arsenate of lead, arsenite of lime, and Paris green 
are notable examples of such insecticides. 

For a long time Paris green was the most important of 
the arsenical insecticides. It is a chemical combination of 
arsenic and copper, containing, when pure, about fifty-five 
per cent of arsenic. It is in a finely powdered condition, 
and, when placed in water, the fine particles do not dis- 
solve, but remain in suspension. Because of this fact, one 
of the most popular ways of applying arsenical poisons to 

plants in danger from the attacks of 
biting insects, is in a water mixture 
by means of a force pump and spray 
nozzle. 

In its simplest form this process 
consists of mixing about a teaspoon- 
ful of the poison in a pail of water, 
stirring thoroughly to get the powder 
evenly distributed through the water. 
A small force pump, to which is at- 
tached a rubber tube with a spray 
nozzle at the end, is then set in the pail. By working the 
handle of the pump, the water with the poison particles 
in suspension is forced through the tube and nozzle, corn- 




Bucket 
Pump 



INSECTICIDES AND THEIR APPLICATION 157 

ing from the latter in a mistlike spray. This spray is di- 
rected upon the leaves of the plant to be protected, covering 
each leaf with the liquid. 

As soon as the spraying ceases, the water begins to evap- 
orate and rapidly disappears, leaving the particles of poison 
more or less evenly distributed over the. foliage. There 
they remain for some time, so that in case a biting insect 
feeds upon the poisoned surface it will eat some of these 
particles and be killed. 

Fortunately the insoluble poison is not absorbed into 
the tissues of the plant, so that the process can gener- 
ally be carried on without danger to the consumers of 
the crop. In the course of a few weeks the particles of 
poison are washed away by rain or dew, or blown away 
by the wind, or dissipated through the action of the sun- 
shine. 

A substance that is used to destroy insects is called an 
insecticide or insect killer. Thus Paris green is an insecti- 
cide. So also is lead arsenate, hellebore, powdered to- 
bacco, and insect powder. Each of these substances may 
be applied to plants in mixture with water, or most of them 
may be dusted on in the form of a dry powder. One may 
sometimes use for this purpose simply a porous bag, out of 
which the powder is sifted. It is better, however, to apply 
the material by means of one of the many kinds of powder 
bellows manufactured for this purpose. With one of the 
better forms of these, a pound of Paris green can be evenly 
distributed over an acre of potato vines. 

Paris green is so powerful a poison that it is often de- 
sirable to dilute it with some substance like land plaster, 
air-slaked lime, or flour. The proportion of poison to dilu- 
ent varies greatly with different users. One part of poison 
to twenty parts of diluent serves the purpose if the mixing 



i58 



FARM FRIENDS AND FARM FOES 



be thoroughly done. When a good powder gun is used, it 
is not so necessary to dilute the poison. 

During recent years, arsenate of lead has become one of 
the most generally used of arsenical insecticides. It is 
made by combining arsenate of soda with acetate of lead 
in water, and is commonly offered for sale in the form of 
a thick paste. This insecticide has a great advantage over 
Paris green in that it may be applied even to tender foliage 










"* i 



S&< 



- 





A Simple Sprayinc; Outfit 



without injury to the plant. It also remains upon the leaves 
longer than any other arsenical insecticides. Under special 
conditions it may be advisable to prepare the arsenate of lead 
at home, but usually this is scarcely worth while. A dry, 
powdery form of this poison has lately been put upon the 
market, and is likely to be very useful for applying with 
various sorts of powder bellows. 

Trouble has been observed in some Western states in 
injury to the health of trees from the use of arsenate of lead. 
The poison appears to penetrate the soil and be absorbed 
through the roots. On this account arsenic sulphide has 
been substituted in an experimental way, and promises to be- 
come an important insecticide. It is less soluble than other 
forms of arsenic, and also less expensive. 



INSECTICIDES AND THEIR APPLICATION 159 

External Poisons 

The petroleum oils are among the most important of the 
contact-killing insecticides. For general use kerosene is 
the most convenient of these oils. As kerosene does not 
mix with water, dilution with this liquid is not practicable. 
It has been found, however, that kerosene may be safely 
and effectively used, provided it is first emulsified with hot 
soapsuds. This is generally accomplished by adding two 
gallons of kerosene to one gallon of a solution made by dis- 
solving half a pound of common hard soap in one gallon 
of boiling water, and then churning the mixture by forcing 
it back into the same vessel through a force pump. A 
creamy emulsion will thus be formed. Before it is ap- 
plied, this emulsion is to be diluted with nine or ten parts 
of water. It is better to use soft water or rain water for 
the dilution. 

The undiluted emulsion may be kept for some time, stored 
in a dark, cool place. When needed, the required amount 
may be measured out and mixed with three or four parts 
of boiling water, cold water being added to fill out the di- 
lution. 

Kerosene emulsion is an excellent remedy for insects 
that suck the sap of plants through pointed beaks, such as 
the plant lice and the chinch bugs. It kills by contact, but 
does not remain upon the plant in an effective condition. 
It is applied in a fine spray. 

Various forms of crude petroleum have recently come 
into use against scale insects. Some proprietary insecti- 
cides contain heavy oils so treated as to mix readily with 
water, so that they are very easy to spray upon dormant 
trees. 

The lime-sulphur wash is one of the most efficient con- 



160 FARM FRIENDS AND FARM FOES 

tact-killing insecticides. It is used chiefly on dormant trees 
to kill the San Jose scale and other scale insects. The 
usual formula is : Unslaked lime, 20 pounds ; sulphur, 
15 pounds; water, 50 gallons. The lime is slaked in 10 or 
1 5 gallons of water ; then the sulphur is added and the prep- 
aration boiled for an hour. The rest of the water is then 
added and the mixture is ready for use on dormant trees 
only. 

In place of this mixture boiled by outside heat, lime-sul- 
phur washes have lately been made by utilizing the heat of 
the slaking lime. These are called self-boiled mixtures and 
usually have less sulphur and lime than the formula given 
above. They are often used for summer spraying, being 
effective against both scale insects and various fungous 
diseases. 

Strong soapsuds have a decided insecticide value for use 
against plant lice and other soft-bodied insects. Whale-oil 
soaps are more effective than ordinary soaps, and are gen- 
erally used as insecticides. 

Pyrethrum powder commonly sold as insect powder is 
a standard insecticide for use against house flies and cer- 
tain other insects. It consists of the powdered flower- 
heads of the pyrethrum plants — a genus of composite 
flowers which are often grown in gardens for their orna- 
mental value. This powder is generally used dried, but 
may be applied as a spray — by mixing one ounce of pow- 
der with two gallons of water and letting it stand over 
night, or by boiling for a few minutes. 

Tobacco is another contact-killing insecticide which is 
frequently used with good results against plant lice and 
vermin on domestic animals. The refuse stems are some- 
times utilized in greenhouses as a mulch for growing crops 
to prevent the development of aphides. These stems are 



INSECTICIDES AND THEIR APPLICATION 161 



also ground into a powder which is applied directly to the 
insects. A tobacco decoction is frequently made by boil- 
ing the powder or stems 
in water or by pouring 
boiling water over them. 
There is thus formed a 
concentrated solution 
which is diluted with cold 
water until there are about 
two gallons of decoction 
for each pound of tobacco 
used. The decoction may 
be sprayed upon the in- 
sects to be killed. Per- 
haps the way in which tobacco is most commonly used as 
an insecticide is that of slowly burning the stems in green- 
houses, producing a smoke which permeates the plants 
and kills the pests upon them. 




x^ 



Vapors and Gases 

There are certain insects which may most easily be 
killed by the use of vapors or gases. For this purpose 
bisulphide of carbon and hydrocyanic acid gas are chiefly 
employed. The former is a liquid that readily volatilizes 
on exposure to the air and kills all insects with which it 
comes in contact. It is used to best advantage against in- 
sects affecting dry seeds and grains in storehouses, and 
against insects affecting the roots of plants. 

Hydrocyanic acid gas is a deadly vapor made by pouring 
sulphuric acid on cyanide of potassium. It is used to de- 
stroy white flies in greenhouses and for various enemies of 
citrus fruits in Florida and California. In the case of 



162 FARM FRIENDS AND FARM FOES 

these fruits, tents are placed over the trees before the gas 
is generated. 

In California sulphur is used as a remedy for red spiders 
and certain leaf hoppers. The sulphur vaporizes in the 
hot sunshine, and the fumes are fatal to the insects. In 
greenhouses sulphur is also used by painting heating pipes 
with it so that the fumes will be given off. 

OBSERVATIONS FOR PUPILS 

i. Make a list of the injurious plant-feeding insects that you know 
which may be killed by internal poisons. 

2. Make a similar list of those that may be killed by tracheal poi- 
sons. 

3. What insects in your locality must be killed by the use of noxious 
gases ? 

4. In what ways have you seen insecticides applied? 

5. Read such of these references as your teacher may direct : — 

Important Insecticides, Farmers' Bulletin 127. Carbon Bisulphide as an Insec- 
ticide, Farmers' Bulletin 145. Spraying for Orchard Insects, Yearbook Reprint 
480. 



CHAPTER XIII 



The Predaceous Insects 

While a large proportion of the insects that we meet in 
our walks afield are in one way or another injurious to 
cultivated crops or domestic animals, there are vast num- 
bers of species which may be regarded as either beneficial 
or neutral. From the beginning of their lives as eggs 
until their death as adults, the injurious insects are beset 
by a multitude of enemies. Some of their enemies attack 






Tiger Beetles 

them with wide-open jaws, devouring the victims bodily, 
while others pierce their bodies with pointed beaks to suck 
their lifeblood. Yet others insert lancelike ovipositors by 
means of which they leave inside the body of the victim 
tiny eggs that develop into parasites whose attacks are as 
fatal as those of the larger foes. Those insects that de- 
vour the bodies or suck the lifeblood of their victims are 
called Predaceous Insects. 

There are a great many different groups of predaceous 
insects belonging to many families in various orders. 

163 



164 



FARM FRIENDS AND FARM FOES 



There is room in these pages for a discussion of only a few 
of the more important of these groups. 

Predaceous Beetles 

Among the notable foes of injurious insects the Pre- 
daceous Ground Beetles (Carabidae) hold a high rank. 
They are active, voracious beetles, having hard, flattened 
bodies, strong legs, and large jaws. They hunt commonly 
upon the ground or in trees and shrubs for caterpillars and 
other insects that may serve as food. Cutworms, army 
worms, gypsy moth caterpillars, and similar grass and leaf- 
feeding larvae are especially likely to be caught by them. 




Ground Beetles 



Many Ground Beetles are black in color, but a few are 
greenish blue, and some are marked with golden spots. 
Specimens are nearly always to be found beneath boards 
or logs lying loosely on the soil surface. 

The larvae of most of these ground beetles are also pre- 
daceous. They are very active, and are provided with 
large jaws for catching and devouring their prey. 

The Tiger Beetles (Cicindelidae) are perhaps of less 
economic importance than the Ground Beetles because they 



THE PREDACEOUS INSECTS 



165 




Tiger Beetle 
Larva 



hunt their prey in a more restricted range. Tiger Beetles 
are to be found in open sunny spaces, as along highways 
and byways, or on the sandy shores of lakes 
and streams. They greedily devour such 
insects as they find in their eager wander- 
ings. The long legs are fitted for rapid run- 
ning ; the large eyes are fitted for seeing over 
a wide area; the strong jaws are fitted for 
sudden grasping, and the well-developed 
wings are fitted for quick flight on the approach of danger. 
The wing-covers, legs, and body wall are very hard and 
often brilliantly colored in metallic hues. 

In early life the Tiger Beetles are curious grublike 
larvae that live in burrows in hard ground, as along beaten 
paths and sandy shores. These burrows are vertical holes, 
nearly as large as the diameter of a lead pencil. The larvae 
have a strangely flattened head with long, widespread- 
ing jaws. Each lies in wait at the top of the burrow, 
practically invisible on the smooth surface of the ground. 
When an unsuspecting caterpillar or other insect passes 
over the waiting head, the jaws grasp the victim, which is 
quickly dragged into the burrow to be devoured at leisure. 
From an economic point of view the familiar little Lady- 
bird Beetles (Coccinellidae) are perhaps 
the most important of all the predaceous 
beetles. These brightly colored little crea- 
tures, in both their larval and adult stages, 
feed chiefly upon the destructive aphides 
or plant lice, destroying every year billions 
of the pests. 
Wherever you find a colony of aphides 
sucking the sap from living plants, there you are likely to 
find some of the Ladybirds at work. They lay their eggs 




Ladybird Beetle 
and Pupa 



i66 



FARM FRIENDS AND FARM FOES 




Blister 
Beetle 



on leaves or stems, the eggs of the larger sorts bearing a 
general resemblance to those of the familiar Colorado po- 
tato beetle. These eggs soon hatch into the curious Lady- 
bird larvae which also feed upon the aphides, destroying 
great numbers of them. After some weeks of 
feeding, the Ladybird larvae attach themselves to 
leaf or bark and change to pupae, soon to change 
again to adult beetles. 

While most of our common Ladybird beetles 
* l^jP J feed chiefly upon aphides, some species devour 
I \ bark lice. One of the most noted kinds of 
beneficial insects is the celebrated Australian 
Ladybird — Vedalia cardijialis. This insect was 
introduced into California to destroy the fluted scale — a 
destructive pest in orange groves. The experiment was 
quite successful, for the scale insects were materially 
checked by their little foes. 

Predaceous Bugs 

Probably the most important predaceous insects in the 
order of true bugs are the Soldier Bugs (Pentatomidae). 
These belong to the genus Podisus ; 
they are of moderate size, the larger 
common ones being slightly less than 
an inch long, with flattened bodies, 
well-developed legs, and strong, 
sharply pointed beaks. There are about a dozen species, 
several of which have a horizontal spiny projection on each 
side of the back behind the head. 

The Spined Soldier Bug is one of the largest and most 
widely distributed of these insects. The adults pass the 
winter under loose bark, fallen trees, loose leaves, or other 
shelter. In spring they come forth and attack such cater- 




Soldier-buq 



THE PREDACEOUS INSECTS 167 

pillars or other soft-bodied insects as they can find, sucking 
their lifeblood greedily. They lay the rather large, more 
or less barrel-shaped eggs in clusters upon leaves or bark. 
The eggs soon hatch into tiny bugs that at first get food 
by sucking the sap of various leaves or tender stems. 

During the next few weeks these young Soldier Bugs 
molt several times, increasing in size each time. The 
time when they stop sucking the sap of plants to begin 
upon the blood of animals seems not to be known, but 
it is probably when they are about half grown. During 
the rest of their lives they seem to prefer animal juices to 
those of plants, and go eagerly about in search of victims. 
Among the most important of these are the larvae of the 
Colorado potato beetles, asparagus beetles, cabbage worms, 
web-worms, tussock caterpillars, cotton worms, leaf rollers, 
codling moth larvae, sawfly larvae, and even the curious 
walking sticks. 

This or a closely related Soldier Bug is one of the com- 
monest predaceous enemies of the tent caterpillars, occur- 
ring frequently in the nest of the American tent caterpillar. 

While the Soldier Bugs, as befits their name, are bold 
freebooters, constantly invading new areas in search of 
victims, the Ambush Bugs (Phymatidae) have quite a dif- 
ferent habit. These take up their quarters in flowers or 
other shelter where they patiently lie in ambush until some 
unsuspecting insect comes within reach of their curiously 
made, grasping arms. As soon as it has seized the victim, 
the pointed beak serves to suck out the body juices, and 
the remains are cast aside. 

Five species of Ambush Bugs are recorded for our region. 
Only one of these is so abundant and widely distributed as 
to be generally known. It may be called Wolff's Ambush 
Bug and is in color a curious mixture of green and yellow. 



i68 



FARM FRIENDS AND FARM FOES 



It is especially likely to be found in yellow flowers, waiting 
to capture unsuspecting butterfly visitors. 

The Wheel Bug is a common predaceous insect in the 
Southern states. It is of good size, being more than an 
inch long, with a sharp beak and a curious crest on the 
thorax that gives it its common name. It feeds largely 
upon caterpillars, and belongs to the family of Assassin 
Bugs (Reduviidae). 

Two-winged Flies 

Of the great number of families of two-winged flies com- 
paratively few are predaceous. The most distinctive of 
these are the Robber Flies (Asilidae), a group of hawklike 
creatures, some of which may often be seen in open fields. 

Nearly a thousand distinct species 
are found in North America. The 
more familiar forms have powerful 
wings and long legs and abdomen. 
They commonly rest on low shrubs 
or plants whence they can readily 
pounce upon any flying insect that 
passes near. Honeybees are so 
often killed by them that in some 
regions these flies are called bee 
killers. Such victims are caught by 
the powerful legs, and quickly sucked dry by the voracious 
robbers. A few species bear a striking resemblance to 
bumblebees and wasps, from which they are at once distin- 
guished by having but one pair of wings. 

So far as their earlier stages have been described, the 
larvae of these flies seem to be largely predaceous also. 
They live in damp soil and rotting wood, apparently feeding 
upon the other insects found in such situations. 




Robber Fly 



THE PREDACEOUS INSECTS 169 

A colony of aphides or plant lice offers many oppor- 
tunities to study the relations of various groups of insects to 
one another. In such a colony there are forms of winged 
and wingless aphides as well as several kinds of enemies 
that attack them. Among the latter are the tiny four- 
winged parasites, the young and adult ladybird beetles, and 
the strange Aphis Lions. In addition to these, you can 
generally find, also, a curious footless grub blunt at one end 
and sharply pointed at the other, which impales the plant 
lice one at a time on its pointed end, sucks the lifeblood, and 
casts aside the empty skins. These are the larvae of the 
Syrphus Flies (Syrphidae), many species of which in the 
larval state thus prey upon the aphides. 

The Syrphus Flies are generally a little larger than the 

common house fly and may be found in abundance visiting 

flowers in search of pollen and nectar. The 

mother flies lay their elongated whitish eggs 

on leaves and bark amid colonies of plant lice. 

The eggs shortly hatch into the curious larvae 
i ii-i „ 7 , c 11 . Syrphus 

that prey upon the aphides. When full grown, FLY 

the syrphid larvae change to pupae, still upon 

the leaf or bark, and change again a little later into adult 

flies. 

Four-winged Flies 

The great order of Four-winged Flies — Hymenoptera — 
contains several families that may be classed to a greater 
or less extent in the predaceous group. One of the most 
important of these is that of the Ants, which are so univer- 
sally distributed over the surface of the earth. Most of these 
ubiquitous little creatures have a wide range of food, taking 
almost anything, living or dead. There is no doubt, how- 
ever, that they are important foes of noxious insects, de- 




170 



FARM FRIENDS AND FARM FOES 




White-faced Hornet 



stroying unsuspected numbers of eggs, larvae, and later 
stages of plant-feeding insects. 

The Social Wasps (Vespidae) are well-known predaceous 
insects. The adults build paper nests in which the young 
are reared, being fed largely with various insects that the 
worker wasps catch for them. These workers also feed 

freely upon such insects, though 
they also eat the nectar of 
flowers and other kinds of food. 
The various groups of Soli- 
tary Wasps must also be classed 
with the predaceous insects, 
though their peculiar habits 
ally them in a way with the true 
parasites. The Mud Wasps 
and the Digger Wasps provision their cells and burrows with 
flies, grasshoppers, caterpillars, spiders, and other crea- 
tures. These victims are paralyzed by the sting of the wasp 
so that they lie helpless in the cell in which the wasp Qgg 
is laid. This egg soon hatches into a larva that feeds upon 
the paralyzed prey, finally transforming to a pupa and later 
to an adult wasp. 

Other Orders 

Comparatively few important predaceous families are 
found in the other orders of insects. Some of these, how- 
ever, are friendly insects of great value, serving a notable 
purpose in the economy of nature. 

What the swallows are among the birds, the Dragon Flies 
are among the insects. These powerful creatures are won- 
derfully adapted to their life work. With enormous eyes 
that see in practically all directions, with powerful wings 
that carry them with lightning rapidity through the air, with 



THE PREDACEOUS INSECTS 



171 




DRAGON-FLY 



a long abdomen that serves admirably as an aerial rudder, 
and with strong front legs and great jaws fitted for grasp- 
ing and biting their victims, they may in- 
deed appear as formidable dragons to less 
fortunate insects. In their earlier stages 
these insects develop in the water, where 
they are also predaceous. 

The Dragon Flies are commonly di- 
vided into two groups : those in which the 
wings are held vertically when the insect 
is at rest are called Damsel Flies; those 
in which the wings are held horizontally 
when the insect is at rest are called 
Dragon Flies. 

Among the many parasitic and predaceous insects to be 
found amid colonies of plant lice, the Aphis Lions are per- 
haps the most remarkable. These are 
long-legged, slender-bodied creatures 
with strange long jaws between which 
they grasp their prey while they suck 
the body dry. They are the larvae of the 
Golden-eyed Lace-winged Flies (Chryso- 
pidae). 

The curious Mantids of the order Or- 
thoptera are also remarkable predaceous 
insects. They are closely related to the 
walking sticks and lie in wait till vari- 
ous insects come within reach of their 
grasping front legs. The native Praying 
Mantis is not uncommon in the South- 
ern states, while another species from 
Europe has lately been introduced into New York state. 
There are, of course, many predaceous creatures among 




Egg Mass of 
Mantis 



172 FARM FRIENDS AND FARM FOES 

the spiders, mites, and myriapods, related to the insects 
proper. But the limitations of space forbid their discus- 
sion here. 

OBSERVATIONS FOR PUPILS 

Predaceous Beetles 

i. If you can find any of the Predaceous Ground Beetles, keep them 
alive in a vivarium for a few days. Furnish cutworms, cabbage worms, 
or other caterpillars for food. 

2. See if you can find any Tiger Beetles along paths and roadsides. 
Which way do the beetles face when they alight — toward you or not ? 
Catch two in an insect net. Keep them in a vivarium and furnish 
caterpillars for food. 

3. See if you can find any burrows of Tiger Beetle larvae in smooth- 
trodden ground. 

4. Bring in a few Ladybird Beetles and keep in a vivarium. Furnish 
aphides for food. See if you can find any Ladybird larvae, pupae, or 

eggs- 

5. For a fuller account of Tiger Beetles read Life Histories of 
American Insects, pages 19-27; of the Ladybird Beetles, Stories of 
Insect Life, Second Series, pages 49-55. 

Predaceous Bugs 

1. Look in tent caterpillars' nests in spring to see if you can find any 
Soldier Bugs. Or later in the season see if there are any on the potato 
vines. If you find any. keep them in vivaria for a few days and see the 
way they take their food. 

2. In summer or early autumn sweep clusters of herbage for the 
yellowish Ambush Bugs. Study their structure to see the sharp beak 
and the curious front legs fitted for grasping. 

3. If you live where the Wheel Bugs are found, keep one alive and 
watch it feed upon caterpillars. 

4. Read the life story of the Wheel Bug in The Insect Book, pages 
294-296. 

Two-winged Flies 

1. On warm days look for the Robber Flies along sunny roads. 
Listen to the quick buzz as they fly up and watch how they lie in wait 
for prey. 



THE PREDACEOUS INSECTS 



x 73 



2. Examine a colony of plant lice carefully. Try to find the white 
eggs, the footless larvae, or the curious brown puparia of some of the 
Syrphus Flies. Watch one of the larvae through a lens to see the way 
it impales its victims. 

3. Read the account of the Robber Flies in The Insect Book, pages 
141-143; of the Syrphus Fly in Stories of Insect Life, First Series, 
pages 50-51. 

Ants and Wasps 

1 . Watch the surface of an ant's nest to see if any insects are carried 
to it. 

2. Watch wasps and hornets as they fly about porches and near 
houses to see if they catch flies and other insects. 

3. Open the cells of a Mud W'asp's nest to see the paralyzed spiders 
or caterpillars inside. 

4. Watch the places where Digger Wasps make their burrows to 
see the insects at work. 

5. Read such of the following accounts of the life histories of wasps 
as you have access to : — 

The Insect Book, pages 18-30. American Insects, pages 490-510. Nature Biog- 
raphies, pages 102-106. Life Histories of American Insects, 147-178. Stories of 
Insect Life, Second Series, pages 24-29, or the book by Professor and Mrs. Peck- 
ham, entitled The Solitary Wasps. 



Other Predaceous Insects 

1. Watch the Dragon Flies and Damsel Flies in summer. Notice 
the position of the wings when the insects alight. 

2. Read the account of Dragon Flies in American Insects, pages 75- 
89 ; also the accounts of the Praying Mantis in The Insect Book, pages 
326-328 ; Stories of Insect Life, Second Series, pages 63-68. 




CHAPTER XIV 



The Four-winged Parasites 

It is fortunate for mankind that almost all species of in- 
jurious insects have insect enemies that destroy them. 
These insect enemies are divided into two groups as regards 
the methods by which they kill their victims. There is no 
hard and fast line to be drawn between these groups, but 
in general we may safely say that the insects which destroy 
other insects are either parasites or predaceous insects. As 
a rule, the parasites develop in the larval state within the 
bodies of their victims, and, as a rule, the predaceous insects 
feed, sometimes during the earlier stages, sometimes during 
their adult stage, and sometimes during both, upon their vic- 
tims, attacking them from the out- 
side either by thrusting a pointed 
beak through the skin and sucking 
their lifeblood, or else by devouring 
them bodily. 

The Ichneumon Flies 

One of the most important groups 
of parasitic insects is that of the 
Ichneumon Flies. These are slen- 
der-bodied, more or less wasplike 
creatures, with four wings, long 
antennae, and well-developed legs 
adapted for running. You may very often see them run- 
ning rapidly over the surface of leaf or bark, in search 

174 




Ichneumon Fly ovipos- 
iting in Cocoon 



THE FOUR-WINGED PARASITES 



175 



of victims in which to lay their eggs, constantly vibrating 
their antennae. Oc- 
casionally, also, you 
may see them visit- 
ing such flowers as 
have the nectar 
freely exposed to lap- 
ping by their short 
tongues. Or you 
may see them in the 
evening as they fly 
about a light to 
which they are at- 
tracted. 

The Ichneumon 
Flies vary greatly 
in size, form, and 
habits. Some are so 
minute as to be barely 
visible to the un- 
aided eye, while 
others measure sev- 
eral inches in length, 
with long antennae 
and slender oviposi- 
tors extending be- 
hind the abdomen. 

Among the largest 
of the Ichneumon 
Flies are the inter- 
esting brown insects 
called the Ophion 
r lies. The life his- Long-tailed Ichneumon Fly 




176 



FARM FRIENDS AND FARM FOES 



tory of one of these in brief is this : The adult fly de- 
posits its egg within the body of a caterpillar, especially the 
caterpillars of the large silkworm moths, like the polyphe- 
mus moth or the cecropia moth. This egg shortly hatches 
into a small white footless maggot that absorbs the body 
juices of the host, as the victim is often called, but at first 
does not seriously interfere with its development. The 
caterpillar with its enemy inside continues to feed and grow 
for some time. It is commonly able to spin its cocoon and 
perhaps change to a pupa within the cocoon before the 
larva of the parasite becomes so large as to kill the host. 
It does kill it, however, finally, and then within the protect- 
ing shelter of the host's cocoon, 
the larva of the Ophion Fly 
changes to a chrysalis. The fol- 
lowing spring it will change again 
to an adult fly, like the one that 
laid the egg in the caterpillar so 
many months before. This fly 
is provided with sharp jaws by 
means of which it gnaws its way 
out of the cocoon and flies freely 
about. It has thus completed 
the cycle of a parasite's life. 

Sometimes the egg of the par- 
asite is not laid within the cater- 
pillar until after it has spun its 
cocoon. This is often the case 
with certain medium-sized Ich- 
neumon Flies of the genus 
Pimpla. These may sometimes be seen standing upon the 
cocoons of the common apple-tree tent caterpillar, with the 
ovipositor thrust down through the cocoon in the manner 







Ichneumon Fly and Butter- 
fly Chrysalis in which it 
developed 



THE FOUR-WINGED PARASITES 



177 




Ichneumon Flies 



illustrated on page 174. The egg develops within the 
body of the host into a white footless maggot that soon 
matures as a larva and changes to a pupa, which in turn 
shortly changes into an adult Pimpla. 

Many of the Ichneumon Flies deposit their eggs within 
the burrows of larvae that bore in the stems of herbaceous 
plants or the bark or trunks of shrubs and trees. In such 
cases, it evidently would be difficult for the mother parasite 
to find precisely the location of the burrowing larva, so she 
simply deposits her egg within the burrow of the latter, 
and the little larva that hatches from this egg is generally 
provided with some method 
by which it is able to reach 
its victim. Instead, however, 
of developing on the inside 
of its host, it usually simply 
attaches itself to the skin and 
sucks its lifeblood from the outside. It finally kills the 
host, becomes full-grown as an Ichneumon larva, and changes 
first to a pupa, and a little later into an adult fly that is able 
to eat its way out through the bark of the plant. 

MlCROGASTER FLIES 

One of the most abundant groups of the Ichneumon 
Flies is that of the Microgaster Flies. These are rather 

small insects that deposit their 
eggs in smooth-skinned caterpil- 
lars of many kinds. As a rule, 
each female fly is provided with 
a pointed ovipositor with which 
she. can pierce the skin of the caterpillar to insert her eggs 
within its body. These eggs shortly hatch into tiny mag- 
gots that develop at the expense of the tissues of the un- 




Cocoons of Microgaster 
Flies 



178 



FARM FRIENDS AND FARM FOES 



fortunate host. In a few weeks the maggots become full- 
grown, and then each burrows its way out through the skin 

of the victim. Once outside, 
each maggot spins some sort of 
silken cocoon within which it 
changes first to a pupa, and 
later to an adult Microgaster 
similar to the one that laid the 




Caterpillar with Cocoon 
Mass of Microgaster Para- 
sites 



There is much variation in 
the color, form, and arrange- 
ment of the cocoons of these 
Microgaster Flies. Some are 
white, others yellow. Some are 
formed singly, others side by 
side in a compact mass, and still 
others in a loose mass of fluffy 
silk. 

There is also great variation 
in the number of parasites to a single caterpillar. Some- 
times there is but one parasite to a host, as in the case of 
certain leaf miners, sometimes there are only a few, but 
more commonly there are a great many — several hundred 
in the case of the tomato worm and other sphinx cater- 
pillars. 

Plant-louse Parasites 

Almost any colony of plant lice will furnish examples of 
the extremely interesting family of tiny flies that prey 
especially upon the aphides. These are little four-winged 
flies so small as to be barely visible to the unaided eye, 
which develop in their younger stages in the bodies of the 
plant lice, and cause the death of untold billions of these 
vexatious pests. 



THE FOUR-WINGED PARASITES 



179 





Aphis with parasite 
larva inside 



PARASITE 
of 

GRAIN APHIS 

MAGNIFIED 




Aphis Killed by 
parasite 



A considerable proportion of these tiny parasites belong 
to the genus Aphidius. The fly generally deposits her egg 
within the abdo- 
men of the aphid. 
The Qgg shortly 
hatches into a 
tiny footless 
maggot that lives 
within the body 
of its , host, ab- 
sorbing the ma- 
terials of growth 
from it, and often 
being visible 
while the host in- 
sect apparently 
is still alive. Fi- 
nally the parasite larva becomes fully developed, absorb- 
ing practically all the contents of the aphid's body, kill- 
ing it, and leaving only the inflated skin of the latter to serve 
as a protection to the parasite. Within this brown inflated 
skin, the larval parasite changes to a pupa and very soon 
afterward changes again to a tiny fly, resembling the one 
that laid the Qgg. This fly gnaws out a circular piece in 
the skin of the dead host, making a hole through which 
it emerges to continue the good work of aphis destruction. 

Very often these little parasites are important means of 
checking outbreaks of destructive aphides. The parasite 
of the grain aphis, illustrated herewith, is a notable example 
of this. Under certain conditions which are favorable to 
the development of the plant louse, but not favorable to the 
development of the parasite, the former become exceedingly 
destructive in the grain fields of the South and West. 



180 FARM FRIENDS AND FARM FOES 

Under ordinary conditions, however, this pest seems to be 
held in check to a great extent by the tiny fly that develops 
in enormous numbers at its expense. 

Primary and Secondary Parasites 

The ichneumon flies discussed in the previous pages de- 
velop as parasites of various plant-feeding caterpillars. 
They are known as primary parasites. 

It very commonly happens, however, that these primary 
parasite larvae are themselves attacked by other ichneumon 
fly larvae that attach themselves to the former and suck 
their lifeblood. Such parasites of parasites are said to be 
secondary parasites. 

It also happens sometimes that one of these secondary 
parasites is in turn attacked by a third larva that sucks out 
its lifeblood. Such parasites of parasites of parasites are 
said to be tertiary parasites. 

Perhaps you will be able to remember these facts better 
if I quote a famous old rhyme : — 

The little fleas that do us tease, 

Have other fleas that bite 'em, 
And these in turn have other fleas 

And so ad infinitum. 

In general these parasites of parasites are spoken of as 
hyperpa rasites . 

Attention has recently been called by W. F. Fiske to an- 
other important phase of parasitism. It very commonly 
happens that two or even more primary parasites attack 
the same caterpillar. One of these may devour the avail- 
able food so rapidly that the other will die. Or they may 
both become fully developed, but be so dwarfed from the 
limited food supply that they are unable to lay eggs for an- 



THE FOUR-WINGED PARASITES 181 

other brood of parasites. Or they both may die from lack 
of food. 

Mr. Fiske has applied the term superparasitism to this 
excessive parasitism of primary hosts. He classifies the 
various conditions that may exist as follows: — 

I. One parasite lives ; the other dies. 

(a) The survivor preys upon the other as an acci- 
dental secondary parasite. Of common occur- 
rence. 

(b) The survivor destroys the other by bringing 
about the premature death of the host and may 
or may not devour it incidentally. Of common 
occurrence. 

II. Both parasites live. 

(c) Neither is the worse for the circumstances. 
Very rare. 

(d) One or both are so seriously weakened and 
stunted as to bring about a material reduction 
in their capacity for reproduction. Common. 

III. Neither parasite survives. 

(e) This may be brought about through the prema- 
ture death of the host through excessive para- 
sitism (commonly) ; or 

(f) Through the inability of either parasite to 
complete its transformations on the limited 
supply of food. Common. 

If you will stop to think what must be constantly hap- 
pening in the world of insects on account of the existence 
of these many primary, secondary, and other parasites, you 
will see that the relations between them must be very com- 
plicated. A caterpillar that is a great crop pest becomes 
abundant. Its primary parasites soon become abundant 



182 FARM FRIENDS AND FARM FOES 

also, because they can multiply rapidly when their caterpil- 
lar hosts are numerous. And so they tend to check the 
caterpillar outbreak. But when the primary parasite is 
abundant, the secondary parasite can also multiply rapidly. 
So these will tend to check the numbers of the primary 
parasite and thus relieve, so to speak, the pressure upon the 
caterpillars. The case will also be complicated by the 
many examples of superparasitism. Consequently there is 
a constant fluctuation in the numbers of these different in- 
sects — each one now abundant, then scarce — with a ten- 
dency toward a normal level. This complicated condition 
is often spoken of as the Balance of Nature. 

The Chalcid Flies 

The ichneumon flies are not the only important group of 
four-winged parasites. From an economic point of view 
the great family of Chalcid Flies is perhaps of as great 
value, although on account of their smaller size they are 
not so well known. It is believed, however, by Dr. L. O. 
Howard, our foremost authority upon these insects, that 
there are more species in this family than in any other of 
the great order of four-winged flies. 

The Chalcids are very small four-winged flies that develop 
in the earlier stages of other insects. They are especially 
likely to infest the eggs and larvae of butterflies, moths, 
beetles, and sawflies, as well as the larvae of great numbers 
of two and four-winged gallflies, ichneumon flies, wasps, bees, 
and two-winged flies. They are also very destructive to 
scale insects and sometimes develop in plant lice and other 
families of true bugs, as well as in the eggs of tree crickets 
and other members of the order Ortlioptera. 

In the case of many Chalcid Flies the life history seems 
to be as simple as in that of the more familiar ichneumons. 



THE FOUR-WINGED PARASITES 183 

The mother insect deposits one or more eggs in a caterpil- 
lar. The eggs hatch into tiny maggots. The maggots 
grow inside the body of the host, absorbing its substance. 
They finally change to pupae, generally within the body of 
the dead or dying host, to emerge later as fully developed 
Chalcid Flies. 

Many of the Chalcids are parasites of borers, gallflies, 
and leaf miners. As a rule, the larvae in such cases develop 
as external parasites upon their victims. You may often 
find examples of these if you will examine a number of 
leaf-miner cavities. Many other Chalcids are parasites 
upon the larvae of the ichneumon flies — that is, they are 
secondary parasites. In such cases, also, the Chalcid larvae 
generally develop as e -ternal feeders upon the ichneumon- 
fly larvae. 

A considerable number of the Chalcid Flies, however, 
have lives that cannot be told in the few words that will 
give the life history of the others. They go through so 
wonderful a course of development that it has required the 
most careful studies of many scientists for years to trace it 
out. Even now we know but little, and that only in re- 
lation to a very few species. But what we do know enables 
us to explain certain facts -which before were very puzzling. 

If you will bring in a lot of nearly full-grown larvae of 
the Cabbage Plusia and keep them in a vivarium, a good 
many of them will be likely to die because they are in- 
fested with parasites. If you will isolate those that die, 
keeping them in small bottles or boxes so you can see how 
many parasites come from each caterpillar, you will prob- 
ably find that from some there emerge hundreds if not 
thousands of tiny four-winged Chalcid Flies. In one case 
three thousand such flies were counted from one cater- 
pillar. 



1 84 



FARM FRIENDS AND FARM FOES 




Chalcid Parasite of Gypsy Moth 

Eggs 

Magnified 



If you stop to think, you can scarcely fail to wonder 
how it was possible for one or even several mother flies 
to lay so many eggs in a single caterpillar. Indeed, it has 
been found that one fly probably cannot lay more than one 
or two hundred eggs, and it would seem hard to believe 

that a dozen or more of 
these flies laid their eggs 
; j upon the Plusia caterpil- 
lar all at once. But if 
they did not do this, how 
may we account for the 
three thousand parasites ? 
The observations of sev- 
eral European entomolo- 
gists indicate that the life 
story of these parasites is something like this : — 

The Plusia Moth lays its egg upon the cabbage leaf. 
Shortly afterward the Chalcid Fly lays its egg within the 
egg of the Plusia Moth. 

The Chalcid egg remains within the Plusia egg, so that 
the latter hatches into a caterpillar with the unhatched 
Chalcid egg within its body. 

After a time the Chalcid egg hatches, but not into a 
single larva. By a wonderful process its contents develop 
into hundreds of tiny larvae that live on the body substance 
of the Plusia caterpillar. They grow gradually inside 
their caterpillar host. The latter finally dies, and the thou- 
sands of parasites change to pupae within the skin. A 
little later they change to flies. 

So, instead of the original egg developing into one Chal- 
cid Fly as is so often the case, it develops into hundreds 
if not thousands. Suppose a female Chalcid Fly laid an 
egg in each of a hundred Plusia caterpillars, and each egg 



THE FOUR-WINGED PARASITES 185 

developed into a thousand flies. Of how many flies would 
she be the mother ? 

Do you wonder that these parasites are important ene- 
mies of injurious insects, and are often able to check seri- 
ous outbreaks of great crop pests ? 



The Proctotrypid Flies 

The third great group of insect parasites is that of the 
Proctotrypid Flies. These are nearly all very minute crea- 
tures somewhat similar to the chalcid flies. A large pro- 
portion of them develop in the eggs of other insects, sev- 
eral sometimes emerging from a single host egg. Many 
of them are parasites upon parasites, and some undergo a 
development of many larvae from one ^gg, as in the case 
of some of the chalcids. 

There is one giant in this family. It is the strange 
Pelecinus Fly pictured below. Apparently it is a parasite 
of the white grub — the larva of the common May beetle. 
The female Pelecinus is much smaller than the male and 
is a very different-looking insect. 




Pelecinus Fly 



186 FARM FRIENDS AND FARM FOES 

OBSERVATIONS FOR PUPILS 

American Tent Caterpillar 

i . Collect a few nearly full-grown caterpillars from the nests late in 
spring and keep in vivaria, feeding as necessary. See how many of 
them are killed by parasites. 

2. Collect from the nests any cocoons that may be made in them. 
These are pretty sure to be infested by parasites. See how many sorts 
of flies come from them. 

3. See if you can find in the nests peculiar shrunken caterpillar skins 
with a cocoon inside. Keep these and rear the parasites. 

4. Look up these references : — 

Stories 0/ Insect Life, First Series, pages 10-11. Nature Biographies, pages 22-34. 

Cabbage Butterfly 

1. Early in spring look on boards, fences, or the sides of build- 
ings near gardens where cabbages have been planted, for masses of the 
small yellow cocoons of microgaster parasites. Keep such cocoons in 
closed vials or boxes to rear the flies. If two kinds of flies emerge, the 
larger black ones will be the microgaster flies, which are the primary 
parasites, and the smaller flies will be secondary parasites. 

2. Early in spring collect a number of the cabbage butterfly chrysalids 
that may be found in boards and fences near old cabbage patches. 
Keep in small vivaria. From some of them you will be likely to rear 
hundreds if not thousands of small chalcid flies. Count the number 
from one chrysalis. Let the flies escape to continue their good work. 

3. In autumn collect a number of cabbage worms. They may gen- 
erally be found abundantly on cabbages. Keep them in vivaria. See 
how many are killed by parasites. 

4. Read The Insect Book, pages 57-60 ; Stories of Insect Life, First 
Series, pages 16-17. 

Fall Web-worm 

1. Early in autumn collect a score or more nearly full-grown fall 
web-worms and place in vivaria. Several of them are likely to be killed 
by parasites. 

2. Find cocoons of the fall web-worm in which external parasites are 
preying on the larvae. 

3. Read The Insect Book, pages 64-68. 



THE FOUR-WINGED PARASITES 187 

Aphides or Plant Lice 

1. Find some colonies of aphides on some shrub, tree, or herb. 
They are commonly abundant on cabbage leaves. Look carefully for 
brown inflated specimens. These are parasitized. 

2. Place some of these parasitized aphides in small vials and rear 
the adult parasitic fly. Notice the hole through which it comes. 

3. Read Life Histories of American Insects ; pages 197-199. 

Sphinx Caterpillars 

1. Look over tomato vines, grapevines, Virginia creeper, and other 
plants to see if you can find any large sphinx caterpillars bearing on 
their backs the cocoons of microgaster flies. If you find any, place each 
in a vivarium. 

2. Notice whether the parasitized caterpillar eats and how long it 
lives. When the flies emerge, notice whether they are all the black 
microgasters which are the primary parasites or whether there are some 
bright-colored chalcid flies, which are secondary parasites. 

3. Read these references : — 

Life Histories of Americaii Insects, pages 181-188. Nature Biographies, pages 
122-131. 



CHAPTER XV 



The Two-winged Parasites 

In the great order of two-winged flies (Diptera) there 
are many parasites of other insects. A large proportion of 
these belong to the family of Tachina Flies (Tachini- 
dae). These are mostly insects of moderate size, similar 
in appearance to the common house fly but usually some- 
what larger. 

These Tachina parasites have long been recognized as 
among the most important enemies of such smooth-skinned 

caterpillars as cutworms 
and army worms, often 
destroying millions of 
these pests at the time 
of a single outbreak. 
The life history as shown 
by the species that in- 
fests the army worm is briefly this : The adult flies de- 
posit their oval whitish eggs upon the outside of the skin 
of the caterpillar. These eggs shortly hatch into tiny 
larvae by burrowing through the eggshell and also through 
the skin of the caterpillar, finding lodgment among the 
body tissues. Here they rapidly develop into whitish foot- 
less maggots that finally kill the host and emerge to change 
to the pupa state at or near the surface of the soil. They 
soon again change to adult flies to continue the generation 
of the parasite. 

188 




Tachinid of Army-worm 



THE TWO-WINGED PARASITES 189 

Variations in Life Histories 

Until recently the life histories of the other Tachina 
Flies have been supposed to be similar to the development 
of that preying upon the army worm. But the careful 
studies of Dr. C. H. T. Townsend upon the parasites of the 
gypsy and the brown-tail moths show a marvelous variation 
in the life histories of these flies, and establish their great 
value as enemies of hairy caterpillars as well as of those 
with smooth skins. Dr. Townsend found that at least one 
of the flies that preys upon the brown-tail moth deposits 
eggs upon the young caterpillars, the eggs hatching and 
penetrating the skins of the caterpillars, much as in the 
case of the parasite that kills the army worm. But the 
other Tachinid parasites had surprisingly different life his- 
tories, the discovery of which required months of patient 
observation. 

Several species of these flies deposit their small eggs upon 
the leaves where the caterpillars are feeding, the eggs be- 
ing often fastened to the freshly eaten edge of the leaf. 
The eggs are swallowed by the caterpillar with the leaf 
particles, generally escaping injury from the jaws because 
they are so minute. Soon after being swallowed, the eggs 
hatch into tiny maggots that burrow through the wall of 
the alimentary canal into the general body cavity of the 
host. Here they absorb food and grow, finally changing 
to pupae and again to adult Tachina Flies — meanwhile 
causing the death of the caterpillar. 

These observations upon the leaf laying of the Tachinid 
eggs indicated an unsuspected ability on the part of the 
flies to overcome difficulties. Evidently the hairy clothing 
of the caterpillars would prove of no value as a protection 
from parasites if the very food is laden with the eggs of 



190 



FARM FRIENDS AND FARM FOES 



the enemy. But the next species to be studied revealed a 
still different method of reaching the interior of the host. 

Observations upon the development of the Tachinid eggs 
indicated the probability that some kinds of these flies would 
deposit living larvae instead of eggs. Two species were 
especially studied, and it was found that the flies were fur- 
nished with " a long curved sheath, into the base of which 
the ovipositor fits, and which tapers to a microscopically 

sharp point." By means of this 
instrument the flies are able to 
thrust the sheath between the hairs 
of the caterpillar, cut a hole in the 
skin, and insert the living larva in- 
side the body of the victim. From 
the point of view of the parasite 
this method has obvious advan- 
tages : the young larva is placed 
amid favorable surroundings at once 
with no danger that it will find itself 
attached to a molted caterpillar skin. 
And the interesting fact was brought out that various na- 
tive flies have a similar sheath and doubtless a similar life 
history. 

A Remarkable Life History 

It is not strange that Dr. Townsend found a species that 
we may for convenience call the Large-horned Tachina Fly, 
the " most remarkable as regards startling deviations from 
the previously known manner of reproduction" in the 
group. It was at first supposed that these flies would 
deposit their eggs upon the skins of caterpillars in the 
old-fashioned way. To a female fly having this habit, the 
presence of a good-sized gypsy or brown-tail caterpillar 




Tachina Parasite of 

Gypsy Moth 

Magnified 



THE TWO-WINGED PARASITES 191 

should be welcomed as an opportunity for depositing an 
egg and thus fulfilling the chief purpose of her existence. 
Consequently the investigators were puzzled to find that 
these flies not only did not so deposit their eggs, but were 
actually alarmed by the presence of the caterpillars. 

It was easily learned through the study of dead flies that 
the eggs were large elongated objects, too large to be swal- 
lowed safely by the intended victims, — safely, that is, for 
the parasite. Hence it could not be that they were laid 
upon the leaves to be eaten. If they were not to be de- 
posited on or in the caterpillars and were not to reach the 
interior of their hosts by being eaten, how was it to be 
done ? 

The final solution may well be given in Dr. Townsend's 
own words : " After much patient observation and experi- 
ment this question was answered. The flies were found to 
deposit living maggots, not on or in the caterpillars, but, 
most remarkable to relate, on the green shoots, leaf stems, 
leaf ribs, and even sometimes on the surface of the leaves." 
This was not a matter of chance, however, for the flies 
hovered in the air above the leaves where the caterpillars 
were at work, evidently seeking for favorable places for 
depositing the larvae. By some sense — perhaps sight, per- 
haps smell, possibly both — they knew when the caterpil- 
lars were present and could not be induced to deposit on 
branches where they were not present or had not been 
crawling. 

In crawling along, many of these caterpillars of the great 
group of silk spinners have an interesting habit of marking 
their trail by a silken thread which is continually spun from 
the silk glands in the mouth as the larva marches to its 
feeding grounds. This thread serves to guide it back to 
its permanent or temporary quarters when its meal is fin- 



192 FARM FRIENDS AND FARM FOES 

ished. If you will look at a nest of our native tent cater- 
pillars in spring, you will see silken webs leading from the 
tents in all directions. These are made by the individual 
caterpillars on their daily journeys in and out. 

It is evident that the Tachina Fly knows about this trail 
of the silk-spinning caterpillar. And apparently she can 
tell whether it is a fresh trail on which the caterpillar has 
gone out and not returned, or an old one which would be 
comparatively useless for her purpose. " Doubtless," writes 
Dr. Townsend, " the flies larviposit only on freshly laid 
strands which have not lost the odor of the caterpillar." 
Upon this fresh strand of silk she deposits a living larva 
that is wonderfully adapted to making its way in the world. 
On the hind end of its body there is a curious sucker-like, 
membranous, cup-shaped case, by means of which the tiny 
maggot is fastened to the leaf on or near the silken thread. 
On the front end of its body is a slightly sickle-shaped hook, 
admirably designed for rending the skin of the caterpillar. 
Thus it is anchored in the path of its prospective victim 
with its stiletto ready for business at a moment's notice. 
As long as all is quiet, it lies lazily down, but on any dis- 
turbance, such as would be made by the homeward return 
of the caterpillar, our young pirate becomes active and 
ready to fasten upon the expected caterpillar. 

If you will examine a good-sized web-worm or gypsy 
moth caterpillar you will find that it is well protected by its 
hairy covering along its back and sides. But on the lower 
surface, the skin is more exposed, and it is obvious that this 
Tachinid larva lying in wait with its stiletto will find the 
caterpillar as it crawls above it an easy victim for its hook. 
When the mouth hook is thrust through the skin, the pull 
of the caterpillar loosens the hold of the parasite upon the 
membranous case at the hind end of its body and the par- 



THE TWO- WINGED PARASITES 193 

asite remains with its host, working its way through the 
skin to the inside and there remaining until it reaches its 
full development into the adult fly, at the expense of the 
life of its caterpillar victim. 

OBSERVATIONS FOR PUPILS 

1. Examine carefully the caterpillars you find to see if any of them 
show Tachinideggs. 

2. Watch for the development of Tachina Flies from the caterpillars 
you rear in breeding cages. 

Read : — 

The Value of Insect Parasitism to the American Farmer, Yearbook Reprint 
447. The Relations between Birds and Insects, Yearbook Reprint 486. 



CHAPTER XVI 



The Pollination and Fertilization of Flowers 



One of the most striking features of the early spring 
landscape in a fruit-growing region is that of the great 
white masses of cherry blossoms. These are to be seen at 
long distances wherever a cultivated cherry tree is growing. 
If you will pick one of these blossoms and look at it care- 
fully for a moment, you will be 
able to see readily the various 
parts of which each flower con- 
sists. 

Hold the stem in one hand and 
you will see a little green cup at 
its upper end ; this cup is called 
the receptacle. Around the outer 
edges of the cup are five small 
lobes ; these are called the sepals. 
They are greenish and served to 
protect the flower when it was a 
bud. In front of the sepals and 
between them are the five large 
white petals, which make the flower conspicuous. Inside 
the petals are many small pollen-bearing organs called 
stamens ; each stamen consists of a sort of stalk ox filament 
and a pollen bag or anther. Very likely the anther in 
the specimen in hand will have broken open so that the 
powdery pollen is plainly visible. In the center of the 
flower is a single slender vertical object called the pistil. 

194 




Cherry Blossoms 



THE FERTILIZATION OF FLOWERS 



J 95 



Stamen 




CHERRY 
BLOSSOM 



It will be worth while to cut away carefully the stamens, 
petals, sepals, and a portion of the receptacle on one side 
in order to get a complete view of the 
pistil. You will then readily see, es- 
pecially through a hand lens, that this 
pistil consists of an enlarged part at the 
bottom called the ovary, above which 
is a slender stalk called the style, on 
the upper end of which is an enlarged 
portion called the stigma. If now you 
cut away carefully a piece of one side 
of the ovary, you will see within a single little egg-shaped 
object called the ovule. 

If you look carefully with a lens at the glistening surface 
of the receptacle, you will probably see certain drops of 
liquid; these are drops of nectar which the bees gather 
when they visit the blossoms and carry home to make into 
honey. 

A week or so after the cherry trees have begun to blos- 
som, the landscape is lighted up by the beautiful flowers 
of the apple trees. These may be seen at great dis- 
tances, and by their color and odor serve to attract the 
notice of thousands of insects, which may be seen and 

heard flying among the blossoms, 
busily gathering both nectar and 
pollen. 

If you examine an apple blossom 
carefully, you will see that in many 
respects it resembles the flower of 
the cherry, but differs in having five 
styles and stigmas which at their base are united to form 
a compound ovary. In this ovary are five little cells in 
which the ovules are held. There is thus one of these 



Pollination 



fertilization (' 



196 



FARM FRIENDS AND FARM FOES 




bearing Flower 



cells for each style and stigma. You should see the in- 
teresting nectar cup on the top of the ovary, on which 
glistening drops of nectar may generally be found. ' 

Squash Blossoms 

People are sometimes puzzled over the fact that cucum- 
bers and squashes seem to have so many blossoms in pro- 
portion to the number of fruits produced. 
If you examine, however, the flowers 
upon one of these plants, you will soon 
be able to tell the reason for this. You 
will find that most of the flowers consist 
Cucumber: Pollen- only of sepals, petals, and stamens, and 
that such flowers are easily recognized 
from a side view, by the fact that there 
is below the blossom no little cucumber 
or squash to develop later into a fruit. 
These flowers are stamen-bearing or stam- 
ina tc blossoms, and in general they are 
smaller than the other kind of flowers 
found upon the same plants, which con- 
sist of sepals, petals, and a single pistil. 
The ovary of the pistil which you will 
recognize at once as a miniature cu- 
cumber or squash is below the main blossom, but has a 
style that runs up through the center of the flower and 
bears upon its tip a well-developed stigma. These are the 
seed-bearing or pistillate flowers. 

If you should cut open the ovary of one of these pistillate 
flowers, you would find inside a large number of tiny seed- 
like bodies called the ovules. In order that these ovules 
may develop into seeds, it is necessary that some pollen 
from the staminate blossoms should be placed upon the 




Cucumber : Seed- 
bearing Flower 



THE FERTILIZATION OF FLOWERS 197 

stigmas of the pistillate blossoms and should send down 
through the style certain pollen tubes which come in contact 
with these tiny ovules and fertilize them. When they are 
thus fertilized, the ovules will begin to develop into seeds. 
The fact that these ovules are developing into seeds will 
cause the surrounding ovary, which is the outer part of the 
little cucumber or squash, also to develop, and the whole 
will finally mature into a squash or cucumber with the seeds 
inside. 

If you look at these flowers again, you will see that the 
pollen is sticky and well protected within the lobes of the 
yellow corolla. You will also see that the stigma is likewise 
somewhat sheltered by the lobes of its corolla, and it will 
easily be evident that there is no likelihood that the pollen 
will either fall or be blown by the wind from one flower to 
the other. How, then, is it carried ? This is a question you 
can easily answer by a few moments' observation on a 
bright summer day. You will see great numbers of bees 
of many sizes and kinds visiting all these flowers. If you 
watch these bees, you will see that their bodies are more 
or less dusted with pollen and that when they enter the 
pistillate blossoms, some of this pollen is rubbed off upon 
the stigmas. Consequently you will know, that while the 
bees are gathering pollen and nectar to store up in their 
hives or nests, they are also helping the plants by carrying 
the pollen from one flower to another. This carrying of 
the pollen from stamen to stigma is called pollination, and 
the bees which thus bring about this pollination are called 
pollenizers or pollinators. 

If you examine many strawberry blossoms, looking es- 
pecially to see whether they all have about the same num- 
ber of pistils and stamens, you will probably find that 
upon some plants the flowers possess both sets of these 



i g8 



FARM FRIENDS AND FARM FOES 




Staminale 



THE 

INSECT POLLENIZED 



STRAWBERRY 



Pislillate 



organs, while upon other plants you will find that the 
blossoms have an abundance of pistils, but very few sta- 
mens. If you think of this condition for a moment, you 
will easily see that in the case of the latter, pollen must be 
brought from those flowers having many stamens, if the 

little ovules are 
to be fertilized and 
the seeds to de- 

Ofii^2 vel °P- 

If you watch a 

strawberry bed for 
a few moments 
some bright day in May, you will have no trouble seeing 
how this pollen is transferred from one blossom to the 
other, for you are very likely to find a great many insects 
attracted by the white petals of the strawberry blossoms, 
gathering, perhaps nec- 
tar, perhaps pollen, per- 
haps both. Most of these 
insects will be small bees, 
possibly the common 
honeybees, in case there 
are hives of these near 
at hand. Should you 
follow a single bee as she 
goes from flower to 
flower, you would prob- 
ably find that she often 
passes from a pollen- 
bearing blossom to a 
pistil-bearing blossom, 
and after she has thus visited such a flower, if you 
would look through a lens at the stigmas, you would 




7 AM 
MAY12 



A DAY'S 
CHANGES 

IN A 




10 AM 
MAY 12 




3 PM. 
MAY 12 



PEAR 

BLOSSOM 




7 AM 
MAY 13 



THE FERTILIZATION OF FLOWERS 199 

doubtless see that a good deal of the pollen had been left 
upon these. 

You certainly should be now in a position to understand 
what is constantly happening in all strawberry beds. The 
bees are busily at work carrying pollen from blossom to 
blossom, and thus causing the fertilization of the little 
ovules and their development into seed. This growth of 
the seed upon the surface of the future berry causes the 
parts beneath the seeds also to develop into the luscious 
fruit. 

You can easily prove that this development of the berry 
will not take place unless the seeds are fertilized by the 
pollen. For if you cut off the upper part of the pistils 
upon one side of the berry as the petals are unfolding, so 
as to remove the stigmas, and then watch what happens, 
you will be likely to find that one side of the berry which 
is left to be fertilized by the bees will develop and that the 
other side will not develop. You will thus have been the 
cause of forming an abnormal berry of very little value, 
but I hope you will have proved to yourself that the bees, 
which are thus making possible our crops of strawberries, 
are farm friends, without which we should fare badly. 

Cross-fertilized Flowers 

It is evident that in the case of the squashes and cucum- 
bers, as well as of the strawberries, the pollen that occurs 
upon the stigmas of a seed-bearing flower must come 
from another flower. When pollen is thus carried from 
one flower to another, the blossom is said to be cross- 
pollenized and the ovules as a result are cross-fertilized ; 
that is, the ovules are fertilized by pollen from another 
blossom which is usually upon another plant. When a 
flower is pollenized and fertilized by the pollen from its 



200 FARM FRIENDS AND FARM FOES 

own anthers, it is said to be self-pollenized and the ovules 
are said to be self -fertilized. 

As a matter of fact, the great majority of flowering 
plants are cross-fertilized. Many of them have special 
devices for preventing self-pollination. These devices 
include the separation of the stamens and pistils in differ- 
ent flowers, as in the case of the squashes and cucumbers, 
the maturing of the stamens and pistils at different times, 
or a difference in length of stamens and pistils which pre- 
vents the pollen from getting upon the stigmas. One of 
the commonest methods that nature employs in preventing 
self-fertilization is in rendering the pollen incapable of 
fertilizing the ovules of the flower in which it developed. 
Such flowers are said to be self-sterile, and very commonly 
none of the pollen upon a plant is able to fertilize the 
ovules of any of the flowers upon that plant. Not only 
this, but in many cases the pollen of a certain variety of 
apple, pear, or plum is incapable of fertilizing any other 
flowers of the same variety, even upon different trees. 
In such cases the whole variety is said to be self-sterile 
and must be pollenized by flowers of some other variety. 

The discovery that a large proportion of the varieties of 
tree fruits are self-sterile is one of the most important re- 
cent developments in our knowledge of fruit growing. It 
has been observed for a long time that the variety of plums 
called the Wild Goose, when planted alone, will not set fruit, 
even though there be many trees near together. It had 
also been noticed that when other varieties of plums were 
planted near the Wild Goose trees, the latter commonly 
produced abundant crops. An investigation of the cause 
of this, undertaken by M. B. Waite, of the United States 
Department of Agriculture, showed that this lack on the 
part of the Wild Goose trees was due chiefly to the fact 



THE FERTILIZATION OF FLOWERS 201 

that the variety is self-sterile, and requires for the develop- 
ment of fruit the transfer of pollen from some other sort of 
plum. 

Other investigators have also made further studies of the 
subject, the more important of these having been made by 
Bailey, Fletcher, Kerr, and Waugh, with results which are 
of great importance to every fruit grower. 

It has been pretty conclusively shown that in the case of 
a large proportion of orchard fruits, a much more abundant 
crop is produced where cross pollination with another va- 
riety takes place. It has also been shown that in many 
cases there is a decided increase in the size of such fruits. 
This increase is so marked that it is well worth while 
for any fruit grower to take it into consideration in plan- 
ning his orchard. The increase in size is believed by 
Fletcher to be due to the fact that " the foreign pollen gen- 
erally stimulates the fruit to a better growth, because it is 
more acceptable to the pistils, not because it carries over 
the size-character of the variety from which it came." 

In selecting varieties of fruit trees with reference to 
cross-fertilization it is important to choose those which 
blossom at the same time. 



Agencies that carry Pollen 

There are three principal agencies concerned in bring- 
ing about the cross-pollination of plants. These are : — 

1. The wind which carries the pollen for a large propor- 
tion of the forest trees that blossom early in spring, but 
which apparently has comparatively little to do with the 
cross-pollination of the flowers of most fruit trees and cul- 
tivated plants. Such plants are said to be anemophilous or 
wind-loving plants. 



202 FARM FRIENDS AND FARM FOES 

2. Certain birds, especially humming birds, which carry 
pollen from flower to flower for a comparatively few species 
in temperate regions, although apparently in tropical re- 
gions there are many species so pollenized. Such plants 
are said to be omimophilous or bird-loving plants. 

3. Insects of many kinds, especially bees, wasps, butter- 
flies, and flies, which carry the pollen for the great majority 
of flowering plants and in so doing confer an inestimable 
benefit upon mankind. Such plants are said to be ento- 
mophilons or insect-loving plants. 







LEG OF BEE 



CHAPTER XVII 

The Insect Pollinators 

By far the most important insect pollinators of cultivated 
crops are the bees of the order Hymenoptera. The bees 
form a superfamily called Apina, the members of which as a 
rule are known by the fact that under a lens the hairs which 
cover their bodies are seen to be provided with many minute 
barbs. In most cases, also, the first joint of the hind tarsi 
is expanded and hairy, being adapted to carrying pollen. 
The tarsi are the short joints at the ends of the legs, and 
the first is next to the second large joint of the legs, which 
in a great many bees is especially developed into a so-called 
pollen basket. This may readily be seen by examining the 
hind legs of a bumblebee or other large bee. The barbed 
hairs over the body are obviously an adaptation for carry- 
ing pollen, and they enable these insects to become the 
most efficient of all pollen carriers. 

The bees, as a whole, are divided into two great groups 
or families — the short-tongued bees (Andrenidae) and the 
long-tongued bees (Apidae). 

The short-tongued bees collect nectar and pollen from a 
great variety of flowers, but they are not able to insert their 
tongues into the long tubes of flowers in which the nectar 
is deeply concealed. These bees, for the most part, build 
their nests in the ground, burrowing holes into which they 
carry a mixture of nectar and pollen upon which the larval 
bees develop. Most of these short-tongued bees are very 
small, and many of them may readily be found by a few 

203 



204 FARM FRIENDS AND FARM FOES 

minutes' inspection of flowers in which the nectar is easily 
accessible. 

The long-tongued bees may for our present purpose be 
arranged into two principal groups, those that live solitary 
lives and those that live social lives. The former are 
comparatively few and so are of little importance as 
pollinators of cultivated crops. One of the most distinc- 
tive forms is that of the Leaf Cutter Bees, which have the 
curious habit of cutting out pieces of leaves, to use in 
building their nests. Roses and other plants often show 
leaflets in which a rounded piece has been neatly cut out. 
This is generally the work of one of these Leaf Cutter 
Bees. These insects may be recognized from the fact 
that the under side of the body is covered with a brush of 
hairs, which is used in collecting the pollen for provision- 
ing the nests. 

Social Bees 

But the insects to which mankind is indebted beyond all 
others for carrying pollen are the social bees, of which the 
familiar Bumblebee and the domestic Honeybee are typical 
examples. These bees live in colonies, a single colony 
often consisting of a vast number of individuals. To a 
laro;e extent these insects have at least three distinct forms 
in each colony. In addition to the true males and females 
or the drones and queens, there are great numbers of 
workers, which are generally smaller in size and which 
do most of the work of gathering nectar and pollen to 
provision the nests with honey and bee bread. 

The yearly cycle in the life of the Bumblebees furnishes 
a good illustration of the habits of the social bees. Early 
in spring you may often find the large queen Bumblebees 
flying slowly about close to the surface of the ground in a 






THE INSECT POLLINATORS 205 

more or less zigzag fashion. They often alight and explore 
some nook or cranny that seems to promise a favorable 
situation for a nest. These queen Bumblebees are the 
only kind that have been able to live through the winter, 
and they have been sheltered in some deserted mouse nest 
or similar covering. 

When the queen Bumblebee finds a place that she thinks 
suitable for a new nest, she adopts it for the home of her 
future colony. Then she flies to the early spring flowers 
and gathers nectar and pollen which 
she brings to her nest and of which 
she forms little balls of "bee bread." 
This consists simply of a sort of paste 
made by mixing honey and pollen 
together. Upon each of these food 
balls, the queen bee deposits an egg. 

Very shortly each of these eggs 

hatches into a tiny footless larva that bumblebee showing 
J Pollen Masses on 

feeds upon the bee bread and gradu- hind Legs 

ally increases in size. Before very 

long it becomes full-grown as a larva and changes to a 
pupa or chrysalis, and a little later into an adult Bum- 
blebee. These adults are smaller than the queens and are 
the first of the season's broods of worker Bumblebees. 

These worker bees soon undertake a large part of the 
care of the colony. They form the curious and character- 
istic cells which are found so abundantly in Bumblebees' 
nests late in summer, and they gather nectar and pollen 
for the food of the young. The queen bee is thus left 
free to deposit eggs for more broods of future workers. 

Thus the colony passes through the summer, constantly 
increasing in numbers and all working together for the 
good of the great bee family. They visit flowers of many 




206 FARM FRIENDS AND FARM FOES 

different sorts, especially those in which the nectar is 
deeply secreted, as they are able to reach such nectar by 
means of their very long tongues. They go about from 
day to day, performing for mankind a service of inesti- 
mable value and deserving his support and protection. 

Toward the end of summer a brood of males and females, 
or drones and queens, is developed. These come forth 
late in summer or early in autumn, visiting flowers freely 
along with the workers. All, however, except the queens, 
perish when cold weather comes, and only such queens as 
find adequate shelter are able to live through the winter to 
begin again the cycle of the colony. 

Honeybees and Related Insects 

There are many kinds of wild bees, besides the bumble- 
bees, which are useful in the pollination of crops. In 
many thickly settled communities, however, these are not 
so important as are the familiar hive bees, which, from 
the point of view of usefulness to man, have the great ad- 
vantage that they can be introduced into cleanly cultivated 
regions where there are comparatively few places for wild 
bees to breed. In many greenhouses, hives of bees are 
regularly kept to bring about the pollination of cucumber 
crops, a process that formerly required much hand work on 
the part of men. Outdoors in large orchards, such hives 
seem almost as essential for insuring the cross-pollination 
of the millions of flowers to be found upon the hundreds or 
thousands of apple trees. These bees, of course, have the 
additional advantage that they furnish honey to the owner. 

There are many other members of the order Hymenop- 
tera, which may commonly be found upon the flowers of 
plants, seeking nectar or pollen, or both. The wasps, 
hornets, yellow jackets, sawflies, and ichneumon flies may 



THE INSECT POLLINATORS 207 

all be found at times upon flowers, either wild or cultivated. 
So far as cultivated crops are concerned, however, these 
insects are much less important than are the bees, both on 
account of their smaller numbers and the lack of barbed 
hairs upon their bodies for catching and carrying the 
pollen. 

Two-winged Flies 

In the great order of two-winged flies (Diptera) there 
are hundreds of species that freely visit flowers. Some 
come for nectar, some for pollen, some for both. The legs 
and bodies of many of these flies are furnished with hairs, 
to which the pollen becomes attached and by means of 
which it is carried from the anthers of one blossom to the 
stigmas of another. These flies, as a rule, however, visit 
those flowers in which the nectar is more or less exposed 
in shallow cups, and, except perhaps in the case of certain 
fruit crops, they are not nearly so important as pollinators 
as are the social bees. 

Butterflies and Moths 

In the great order of scale-winged insects, the moths and 
butterflies (Lepidoptera), the great majority of species are 
especially adapted to living as adults upon the nectar of 
flowers. Consequently, there are many plants the blossoms 
of which are especially adapted to cross-pollination by 
means of butterflies or moths. These insects have long 
sucking tubes, each of which is commonly coiled like a 
watch spring on the under side of the insect's head. When 
the butterfly or moth visits a flower, however, it uncoils the 
tongue and projects it forward to reach the nectar of 
the blossom. Often these tongues are of extraordinary 
length, and so it is not surprising to find that the flowers 



2o8 FARM FRIENDS AND FARM FOES 

especially adapted to the visits of moths and butterflies 
commonly have their nectar deeply concealed where it 
cannot be reached by most other insects. 

The great group of hawk moths or sphinx moths is one 
of the most interesting from the point of view of pollina- 
tion. By examining a beautiful Easter lily, one can readily 
see the relation between these moths and the pollination of 
such flowers. 

" If you remove one side of the white flower cup, you 
will see that the pistil consists of a long style running the 
whole length of the flower, with the sticky stigmas at the 
end. Grouped on the sides are the stamens, which also 
have long filaments tipped with the anthers at the mouth 
of the flower. Evidently no other insects can get the 
nectar at the base of the cup ; the sphinx moths are the 
only ones adapted to derive benefit from such a blossom. 
But for them the adaptation is perfect. The tongues of 
the larger species will reach the honey, while their heads 
come in contact with the anthers or stigmas and perform 
the pollenizing office. 

" These moths are not day-fliers : they appear at dusk, 
and during the early evening they shoot like meteors from 
blossom to blossom, hovering hawklike in the mouth of 
the flower, while the long tongue is inserted to extract the 
hidden nectar. The immaculate whiteness of the lilies 
renders them conspicuous in the twilight : they then shed 
their perfume most abundantly, and, in some species at 
least, produce the most nectar. These methods the lily 
has developed to attract her pollen-carrying guests. The 
latter also are assisted in the adaptation ; their long tongues, 
the shape of their heads, their large eyes, all are useful to 
the lily, while the swiftness of their flight and the business- 
like way in which they utilize the few hours during which 



THE INSECT POLLINATORS 



209 



they are abroad enable them to pollenize a large number 
of blossoms in a short time." 1 

Some of the other lilies show similar adaptations to the 
visits of sphinx moths, and many of the honeysuckles and 
other flowering plants are adapted to pollination by such 
visitors. 

1 Weed, Ten New England Blossoms. 




Easter Lily 



210 FARM FRIENDS AND FARM FOES 

OBSERVATIONS FOR PUPILS 
The Apple 



1. Make a careful study of some apple blossoms. See if you can 
identify all of these parts : — 

The calyx lobes, which represent the sepals. 

The petals. 

The stamens, each with filament and anther, the latter containing 

pollen. 
The pistils, united in the ovary, with the lower part of the styles 

also united and bearing a fringe of hairs, then separating and 

each having the stigma at the top. 
The nectar cup on the top of the ovary. 

2. See if you can determine how the nectar is protected from ants 
and wingless insects by the palisade of filaments around the outside and 
the hairs upon the united styles in the middle. 

Thrust a sharp pencil point down through the hairs to see how the 
long-tongued bee could get at the nectar while the short-tongued ant is 
excluded from it. 

3. Watch the apple trees on a bright day to see what sorts of insects 
you find visiting the blossoms. 

Make a list of as many different kinds as you recognize. Are 
any of the bees collecting honey ? Can you see them thrust their 
tongues down to get the nectar ? 

4. When it rains much of the time during the blossoming of the 
apple trees, are the bees able to carry the pollen as well as when the 
weather is fair ? 

B 

1. Tell or write a little story with this title : The Mission of the 
Apple Petals. Follow some such outline as this : — 

The pistil in the bud. 

The nectar cup that it covers. 

The purpose in attracting the bees. 

The carrying of the pollen by the bees. 

The fertilization of the flowers. 

The falling away of the petals. 

The development of the fruit. 



THE INSECT POLLINATORS 211 

2. If your story is written, illustrate it by such drawings of petals and 
flowers as seem to you desirable. 

3 . Read : — 

The Pollination of Pomaceous Fruits, Yearbook Reprint 157. 

The Cherry and the Plum 

Make a study of the structure of the blossom and its relation to 
insect visitors in the case of the cherry or the plum. Follow in a 
general way the outline given above for the apple. 

The Strawberry 
A 

1. Examine a number of strawberry blossoms and see if you can find 
some in which there are many pistils and but few stamens, and others 
in which there are both pistils and stamens in abundance. 

2. Watch the flowers on a bright day to see what insects are visiting 
them. Can you tell whether the insects are gathering nectar or pollen 
or both. Do you see any pollen on the bodies or legs of the bees ? 

3. Watch a bee carefully as it goes from one flower to another. Would 
it be likely that some pollen would be brushed upon the stigmas as the 
bee gathers nectar ? 

4. How does the length of the blossoming period of the strawberry 
compare with that of the apple ? Are there more days for the bees to 
cross-pollenize the strawberry than the apple ? 

5. Tie a bit of mosquito netting or cheesecloth over one of the 
pistillate strawberry blossoms before it opens so as to exclude any insect 
visitor. See if a well-developed strawberry is formed after the petals 
fall off. 

B 

1. Tell or write a little story with some such title as this : The 
Strawberry and the Bees. Show how much we owe to the bees for 
carrying the pollen from flower to flower. 

2. Illustrate your story with drawings of bees and strawberry blos- 
soms. 

Cucumbers and Squashes 

A 

1. Examine carefully all the flowers upon a single long stem of a 
cucumber, squash, pumpkin, or melon plant. How many of the 



212 FARM FRIENDS AND FARM FOES 

blossoms are pollen-bearing or staminate, and how many are seed- 
bearing ? You may know the latter by the little fruit below the flower. 

2. On a bright day see what kinds of insects are visiting the 
flowers. Are they mostly bees? Do you find any bumblebees? Watch 
one of the bees as it comes out of a pollen-bearing blossom and see if 
you can see any pollen upon its body. 

3. Watch one of the bees as it leaves a pollen-bearing blossom. 
Do you find that it ever goes to a seed-bearing blossom ? See if any 
of the pollen is rubbed from the body of the bee upon the stigma of 
the flower. 

4. See if any bees are at work on damp days when there is a little 
mist or rain in the air. If any bees are at work, what kinds are they? 

B 

1. Write or tell a little story with this title: The Pollination of the 
Squash Blossom. If it is a cucumber you observed, make it : The Pol- 
lination of the Cucumber Blossom. 

Follow this outline : — 

The pollen-bearing flower. 

The seed-bearing flower. 

The need of the transfer of pollen. 

The nectar that attracts the bees. 

The color that advertises the nectar. 

The bees that carry the pollen. 

The wilting of the pollen-bearing blossoms. 

The growth of the fruit. 

2. Make a drawing of the side view of each kind of flower, and, if you 
have time, a longitudinal sectional view of the seed-bearing ovary. 



PART III 

FRIENDS AND FOES AMONG THE 

FUNGI 




The Booklet on Fungi 



In addition to the drawings and written pages suggested under Observa- 
tions for Pupils it is easy to enrich the booklet on fungi by mounted speci- 
mens of leaves and other parts of plants affected by various fungous 
parasites. These occur everywhere in autumn, so they are very readily 
obtained. They may be pressed for a few days between papers, changing 
dailv, and then mounted by strips of gummed labels. The name, locality, 
date, and collector should be printed on each sheet. 



CHAPTER XVIII 



Mushrooms, Toadstools, and Molds 

Every one is familiar with the peculiar umbrella-like 
plants called toadstools and mushrooms, which may be found 
abundantly during damp weather, especially in early autumn, 
in fields and woods. They differ from our common plants 
in that they have none of the 
green coloring matter called 
chlorophyl by means of which 
the higher plants carry on 
the processes of their life. 

These toadstools and mush- 
rooms belong to the great 
group of fungi — a group 
which includes a large num- 
ber of species of plants. The 
fungi rank lower in the scale 
of life than the trees and 
herbs which we commonly 

have in mind when we speak of plants, but they serve 
many important purposes in the economy of nature. 

If you will place a well-developed toadstool of the general 
type of the specimen shown in the picture above in the 
position in which it grew, upon a piece of white paper, and 
leave it for a day or two, the paper will probably be covered 
with a fine dark powder. A similar powder will be found 
upon the thin plates hanging down from the upper part 
of the toadstool. If some of this powder be placed under 

215 




2l6 



FARM FRIENDS AND FARM FOES 



a high power of the microscope, it will be seen to consist 
of great numbers of very small, roundish particles. These 
are the spores or reproductive bodies of the mushroom, and 
they may be likened in their relation to the life of the 
fungus to the seeds of the higher plants. 

When these spores are produced by the toadstool out- 
doors, millions of them are blown away by the wind, or 
washed away by the rain. When one of them chances to 

fall upon rich earth, it 
sends out a little tube, in 
much the same way that 
a sprouting seed sends 
out its germinating radi- 
cle. After this tube has 
grown between the soil 
particles a little way, it 
develops branches that 
push about between the 
decaying bits of organic 
matter and absorb mate- 
rials of growth from them. 
Because of this the toad- 
stool is called a saprophyte 
— a plant living upon decaying organic matter. These 
branches in turn send out other branches and thus form 
the spawn, or vegetative portion of the fungus. This is 
also often called the mycelium. 

This spawn continues to develop beneath the surface of 
the soil for a while, until at certain places there are special 
growths from each of which one or more toadstools are 
produced, often appearing suddenly above the surface. 

Each toadstool consists of a stem, above which is a 
wide top suggestive of an umbrella. This top bears on 




Mushroom 

Soil washed from " spawn " and " buttons," 
showing the minute young "buttons" at- 
tached to the strands of mycelium 



MUSHROOMS, TOADSTOOLS, AND MOLDS 217 



the under side curious thin vertical plates, called gills or 
lamellco. On these plates the spores develop, falling from 
them to the ground or being blown away by the winds. 
The plant has now fulfilled the purpose of its existence, 
and it rapidly decays — a process much hastened by the 
numerous insect larvae that feed upon the inner tissues of 
the fungus. 

On most toadstools and mushrooms there may be found 
a ring of thin tissue with ragged edges, hanging from the 
upper part of the stem. This is the remnant of a delicate 
membrane, called the velum, or veil, which covered the 
surface of the cap during its rapid growth. 

Those species of these fleshy fungi which are not 
poisonous and are good 
to eat are called mush- 
rooms, while the poison- 
ous ones are commonly 
called toadstools. No 
general rule can be given 
for distinguishing the 
edible from the poison- 
ous kinds. 

Perhaps a clearer idea 
of the relation between mycelium of the Common Mold 

the mycelium of a fun- From the spore lying near the middle of the 
. . n figure, and strongly swollen, one sees the 

gus and its reproductive 

spores may be obtained 

from the picture above 

of one of the common 

molds that grow upon 

bread or other materials in dark, moist situations. The 

branching threads of the mycelium are spread out over a 

wide space. At certain points rise vertical columns. On 




thick threads of the mycelium arise. From 
the level of the mycelium arise three verti- 
cal, fertile stalks, a, b, c, of which a is still 
very young and that at b is already produc- 
ing a case containing many spores. All 
highly magnified. 



2l8 



FARM FRIENDS AND FARM FOES 



the top of these the spores are produced. Compare it with 
an apple tree : the mycelium corresponds in a way to the 
roots ; the vertical column to the trunk ; the spores to the 
seeds in the fruit. 

Can you not see that this mold is really a plant, though 
it lacks the green coloring matter of our more familiar 
plants ? 

Parasitic Fungi 

The toadstools, mushrooms, and molds are all fungi that 
live at the expense of dead or decaying plant or animal 
materials. They are not of very great interest to agricul- 
ture. I have described them here to lead to a clearer 
knowledge of certain other fungi that are of exceeding im- 
portance to growing crops. These are the fungi that develop 
at the expense of the tissues of living plants ; that is, they 
are parasites rather than saprophytes. They bring disease 
and death to many crops and cause the myriad forms of 
fungous diseases that destroy millions of dollars worth of 
farm and garden produce every year. 




A Dying Mushroom 



CHAPTER XIX 
The Downy Mildews 

The group of fungi commonly called the Downy Mil- 
dews includes several of the most destructive fungous 
enemies of cultivated crops. These parasites grow at the 
expense of the vital tissues of the host plants, penetrating 
between the cells in all directions and sending into the 
cells curious projections that absorb their contents. They 
produce summer spores in untold billions, to be widely 
scattered so quickly that whole fields may seem to succumb 
in a single day. The technical name of the great group to 
which they belong is Phycomycetes. 

Potato Blight 

In America the Downy Mildew of the Potato probably 
causes the greatest loss of any of these parasites, espe- 
cially in the Eastern states. During recent years this 
disease has been generally called the Late Blight to dis- 
tinguish it from the Early Blight of Potatoes due to a 
different fungus. This Late Blight causes not only the 
death of leaves and stems, but also the decay of the tubers. 
It destroys millions of dollars worth of potatoes. 

To get an idea of what happens in a potato field when it 
seems suddenly to blight, let us assume that we have be- 
fore us a green and healthy plant in August. Its leaves 
are busily engaged absorbing the sunshine and converting 
the unorganized substances from the soil, moisture, and air 
into highly organized materials. These it is sending down 

219 



220 



FARM FRIENDS AND FARM FOES 



through its lusty stalks to the little tubers at the ends of 
the underground stems, there to be stored in cells as 
starch. All over the surfaces of the leaves are the tiny- 
openings or breathing pores through which the air gets to 
the leaf cells and through which the surplus water may es- 
cape as vapor. The plant is 
healthy and vigorous and ap- 
parently enjoying its existence. 
But one day a breeze springs 
up that carries particles of dust 
from field to field. In the dust 
are many summer spores of the 
mildew fungus, some of which 
are caught on the surface of 
the potato leaves. The breeze 
is followed by a summer shower 
that soon passes, leaving the 




Potato Leaf affected with 
Late Blight 



foliage wet with glistening 



drops that reflect the hues of 
the rainbow as the sun comes out again. 

In one of these drops a Downy Mildew spore is held. 
It needed only the moisture to cause it to produce curious 
swarm spores that swim about in the water and finally 
germinate, each by sending out a slender tube. The tube 
lengthens, the end creeping along till it reaches one of the 
open breathing pores. It enters this and then begins to 
grow rapidly, sending branching threads between the leaf 
cells in all directions. These threads form the mycelium 
of the fungus. They send into the cells short suckerlike 
branches through which the contents of the cells are 
absorbed. Thus the threads of the fungus penetrate 
through all the tissues of the leaf. Finally they run 
through the petiole to the main stalk and perhaps down 



THE DOWNY MILDEWS 



221 




the stalk to the forming tuber below. Wherever they go, 
they cause the death of the cells of living tissue, breaking 
them up, turning them brown, and causing a foul odor to 
be given off. In the case of the stalks and tubers the 
result appears as a sort of rot. 

The prosperous, healthy plant is thus stricken with a 
sudden sickness that may well be called a blight. The 
tubers are no longer able to increase 
in size through the addition of starch 
cells. A field thus blighted is a 
sight that may well bring dismay to 
the owner who had hoped for a 
bountiful harvest. 

But the parasite is not yet done 
with its stricken host. All this 
growth of mycelium has been but 
a preparation for the development 
of the reproductive spores, just as 
the growth of the mushroom myce- 
lium beneath the soil surface is but a 
preparation for the sending up of 
the spore-bearing mushroom. The mycelium in the leaves 
sends out to the surface vertical branches that bear upon 
their tips the tiny summer spores. These mature quickly 
and are readily carried away by the slightest breeze. Thus 
the disease is able to spread rapidly by means of the bil- 
lions of spores produced. This development of summer 
spores begins soon after the mycelium gets well started, 
often before the whole leaf is affected. Many of these 
spores are likely to be washed through the soil till they 
reach the tubers, and they may develop there, causing a 
characteristic brown discoloration. 

This fungus commonly passes the winter by means of 



Spores on Leaf. Magni- 
fied : a, spore ; b, spore 
germinating; c, spore 
with germinating tube 
entering breathing pore 



222 FARM FRIENDS AND FARM FOES 

the mycelium in the diseased potatoes. When they are 
planted, a new crop of spores apparently is produced, 
either on the seed potato itself or upon the stalks and 
leaves that grow from it. Many of the downy mildews 
have special winter spores by means of which the fungus 
lives from one season to another, but these seem not to 
have yet been certainly found in this species affecting the 
potato. 

The best methods of controlling Potato Blight are the 
planting of tubers from fields in which the disease was not 
present, spraying with Bordeaux mixture, rotation of the 
crop, and the selection of resistant varieties. 

When a parasitic fungus attacks one plant, it is very 
likely to attack other closely related plants. The tomato 
is closely related to the potato. Consequently it does not 
seem strange that there is a Tomato Blight caused by 
the same fungus that causes the Potato Blight. It is 
often destructive in wet summers in the Eastern states and 
during damp winters in southern California. Rotation of 
crops and spraying with Bordeaux mixture are effective 
preventive measures. 

Other Downy Mildews 

A parasite closely related to the Downy Mildew of 
potatoes is the Downy Mildew of Lima Beans. This at 
times is very destructive in many parts of the United 
States, sometimes greatly reducing or almost destroying 
the crop. It appears as a thick white covering upon the 
pods, injuring the tissues of the wall and often extending 
the damage to the young beans inside. It spreads chiefly 
by means of summer spores, and apparently passes the 
winter in the seed in the form both of dormant mycelium 
and of distinct winter spores. 



THE DOWNY MILDEWS 223 

The chief preventive measures are the planting on high 
land of seed gathered from a field where the mildew was 
not present, the rotation of the crop, the destruction of all 
old bean vines, and spraying with Bordeaux mixture. 

The Downy Mildew of the Onion is a widely distributed 
disease that causes serious loss in some parts of the 
United States nearly every year. It attacks the leaves, 
at first causing a yellowish discoloration that may later 
show the white threads of the fruiting fungus. Vast 
numbers of summer spores enable the disease to spread 
rapidly during the growing season, and well protected 
winter spores enable it to live through the winter in dead 
leaves or in the soil. These winter spores appear to be 
able to survive in the soil for two years. Consequently a 
crop rotation in which onions are not grown on the same 
land oftener than once in three years is desirable. Clean 
culture, burning of diseased leaves, and spraying with 
fungicides are also helpful. 

Another Downy Mildew is often destructive to cucum- 
bers, melons, and squashes. It is likely to destroy the vines 
in almost any region when warm damp weather favors its 
rapid growth. It seems to do as much damage in the South 
as in the North, or more, and it often appears as an active 
epidemic quickly blighting the vines over great regions. 
The white mildew that gives off millions of summer spores 
shows on the under surfaces of the leaves. 

Clean culture, burning or deep burying of infested plants, 
rotation of crops, and spraying with fungicides are the chief 
remedial measures against this disease. 

Among the numerous parasitic enemies of the grape the 
Downy Mildew or Brown Rot is at times one of the most 
destructive. In its life history it does not differ essentially 
from the other Downy Mildews. It reproduces in summer 



224 FARM FRIENDS AND FARM FOES 

by summer spores and passes the winter in the form of 
winter spores. It attacks leaves, young stems, and green 
fruits, causing a mildew-like growth on the former and a 
brown rot of the latter. It is prevented by spraying with 
Bordeaux mixture. 

The Brown Rot of the Lemon has recently become a 
destructive disease in California. The fungus attacks the 
rind of the lemon, causing a brownish discoloration and a 
characteristic odor. It is likely to spread through the fruit 
of boxes in storage or in transit, so that it often causes 
serious and unexpected losses. The spores are produced 
on the ground and not on the lemons, but they often reach 
the latter through the water in which the fruit is washed. 
Consequently, one desirable measure of control is the disin- 
fection of this water by the addition of a small amount of 
formalin or some other germicide. Full details of treat- 
ment may be found in the bulletins of the California Experi- 
ment Station. 



OBSERVATIONS FOR PUPILS 

Mushrooms 

i. Bring in afresh mushroom or toadstool. Compare it with the 
picture on page 215. Do you see all the parts there represented? 

2. Place a fresh mushroom upon a sheet of paper and leave over 
night. See if there are spores on the paper in the morning. If so, ex- 
amine under a microscope. 

3. Dig up the soil at the base of the stem of a mushroom to see if 
you can find the mycelium from which it developed. 

4. Look in lawns and pastures to see the " fairy rings " of mushrooms 
that so often occur. See if you can find out the explanation of the pro- 
duction of such rings. 

5. Draw a mushroom and label the parts. 



THE DOWNY MILDEWS 225 

Downy Mildews 

1. Which of these diseases have you known to be present in your 
neighborhood ? 

Downy Mildew or Late Blight of the Potato. 

Downy Mildew of the Tomato. 

Downy Mildew of the Lima Bean. 

Downy Mildew of the Onion. 

Downy Mildew of Cucurbits. 

Downy Mildew or Brown Rot of the Grape. 

2. What preventive measures are used against these diseases in your 
neighborhood? 

3. Make sketches of leaves affected by the disease in the case of such 
of these as you find. 

4. Read Farmers' Bulletin 91. 



CHAPTER XX 



The Smut Fungi 

The Smuts form a distinctive group of parasitic plants 
called by botanists Ustilaginales. The mycelium develops 
in the tissues of the host plant and causes serious injury to 
the parts infested. Spores are developed in the form of 
the blackish powder so characteristic of Corn Smut and 
Oats Smut. These primary spores germinate under favor- 
able conditipns and often bring about 
the development of enormous numbers 
of secondary spores. 

Nearly every one is familiar with the 
Loose Smut disease which so often 
affects the heads of oats, causing them 
to become masses of loose blackish 
powder instead of healthy kernels of 
grain. These black powdery masses 
are composed of millions of the minute 
spores by means of which the fungus 
multiplies. 

These spores appear on the plants when the oats in the 
field are blossoming. At that time the seed envelopes — 
which later form the " chaff " — are spread apart, so that it 
is easy for the spores to lodge inside them. There the spores 
remain, even through the threshing process. 

The spores that have thus been concealed beneath the 
chaff remain in position until the grain is planted. The 
moisture and warmth favorable to the starting of the seed 

226 




Smut Sporidia 
Magnified 



THE SMUT FUNGI 



227 



also cause these spores to germinate. They send out 
tiny tubes that penetrate the young oats plant. The threads 
of the fungus thus get into the growing tissues where they 
continue to develop by sending out numerous branches that 
run through all parts of the stalk. An elaborate mycelium 
is thus formed, and continues to 
develop along with the growing 
oats plant. 

When the grain begins to send 
out its heads, the fungus develops 
a mass of thickened threads within 
the florets. These threads soon 
give rise to millions of blackish 
spores that form the familiar pow- 
der of smutted grain. 

The spores of this fungus are so 
minute that the number in a single 
diseased oats head is almost incon- 
ceivably great. It has been esti- 
mated that a single cubic inch of 
the smut powder would contain 
64,000,000,000 spores. Of course, 
most of these spores never develop. 
With the lower forms of life, Nature produces vast numbers 
of reproductive bodies, with the expectation, as it were, 
that only a small fraction of a per cent will find conditions 
suitable for continued existence. 

Many experiments have shown that Oats Smut may be 
prevented by soaking the seed in diluted solutions of for- 
malin, thus destroying the spores that cause the disease. 

There is another form of smut disease, which is more in- 
jurious to wheat than this loose smut, called the Bunt or Ill- 
smelling Smut, because it has a distinctly disagreeable odor. 




OATS 
SMUT 



228 FARM FRIENDS AND FARM FOES 

With this malady the individual kernels of wheat are affected 
rather than the whole head. Such kernels appear whitish 
or bleached in contrast to the yellow of the healthy grains. 



Corn Smut and Onion Smut 

The curiously swollen kernels on ears of Indian corn 
affected by the Smut are probably familiar to every boy or 
girl brought up in the country. The swelling is due to the 
growth of a parasitic fungus that develops among the grow- 
ing tissues, making the plant cells abnormal and finally 
destroying them. In place of cells of healthy tissue enor- 
mous numbers of tiny blackish spores are finally produced. 
These are the reproductive portions of the parasitic fungus. 
These blackish spores are so fine and light that they are 
readily scattered by the wind or are easily floated from place 

to place by running water at 
times of rain or flood. Un- 
der favorable conditions as 
to warmth and moisture each 
spore is able to germinate 
and produce other or second- 
Corn smut ar y spores, which in turn are 

able to penetrate the tissues 
of the young corn plant and start the disease anew. 

The greatest injury by Corn Smut occurs in gardens 
where corn is grown season after season and the smutted 
ears are left upon the soil. The first step in prevention is 
to destroy promptly all the parts of corn plants that are 
producing the disease, thus checking the development and 
dispersal of the spores. Rotation of crops is also helpful. 
The sorts of Smuts with which most people are familiar 
are those affecting grains in which the fruiting kernels show 




THE SMUT FUNGI 



229 



the injury most plainly. Some parasitic fungi, however, 
develop upon the leaves and stems of other plants. The 
Onion Smut is one of the most important of these. It attacks 
the leaves and bulbs of seedling onions, giving them a char- 
acteristic blackish appearance, and often ruining the crop. 
The spores develop secondary spores called sporidia in 
much the same way that other Smut diseases develop. 

The Onion Smut is especially troublesome on land in 
which successive crops of onions are grown. This is be- 
lieved to be due to the presence of the spores in the soil. 
Consequently, a wise crop rotation is the first preventive 
measure. The spores are also easily carried from field to 
field in the soil adhering to hoes or other tools. Conse- 
quently, care should be taken to prevent this, as well as to 
prevent the washing of the spores from field to field. Clean 
culture and the deep burying or burning of all infested 
plants is desirable. 

The Smut fungus apparently enters the seedling onions 
about the time they come up, rather than later. Conse- 
quently, onions started in special beds and transplanted are 
seldom injured. 

OBSERVATIONS FOR PUPILS 
Loose Smut of Oats 

1. Have you seen smutted oats heads in fields? How much damage 
does the disease do in your neighborhood? 

2. If there is a compound microscope in school, examine the spores 
under a high power. 

3. Bring in a diseased oats head which has not yet burst open ; place 
the stem in a bottle of water and watch it for a few days to see the pro- 
duction of spores. 

4. Make a sketch of a panicle of oats injured by Loose Smut. 

5. Read Farmers 1 Bulletin 250. 



230 FARM FRIENDS AND FARM FOES 

Corn Smut 

1. In your neighborhood, is Corn Smut more injurious to sweet corn 
than to field corn? Is it more destructive in gardens where sweet corn 
is planted in the same place year after year than in gardens where the 
sweet corn is rotated with other crops ? 

2. At what time do the first black spores develop on the smutted 
ears? 

3. Do the people of your locality take pains to cut out and burn the 
diseased plants ? 

4. Make a drawing of a diseased ear of corn. If there is a com- 
pound microscope in school, make sketches of the spores as seen with a 
high-power objective. 






CHAPTER XXI 
The Rusts (Uredinales) 

Few fungous diseases are more widespread in the United 
States or more readily found in any locality than the As- 
paragus Rust. This fungus was described in Europe in 
1805 and had doubtless existed for ages before that time. 
As a serious enemy it first attracted attention in the East- 
ern states in 1896. It spread westward so rapidly that in 
1 90 1 it was very destructive in California. Since then it 
has been generally recognized as the worst obstacle to as- 
paragus culture. 

In a way the life history of this rust is typical of the 
great family to which it belongs. It passes through the 
winter in characteristic spores attached to old leaves and 
stalks, or lying loose upon the soil surface. These are 
called the Winter Spores or teleutosporcs. They are 
stalked, double-celled spores of curious and characteristic 
form. 

In spring these teleutospores germinate as they lie upon 
the ground or upon the standing or fallen asparagus stalks. 
The contents of each cell break through the cell wall and 
run out in the form of a long tube. At the end of the 
tube four partitions develop, so that four distinct cells are 
formed. Then the material in each cell is sent out to form 
a tiny secondary spore or sporidium (plural sporidia). 

These sporidia are so small and light that they are easily 
blown about by the wind. When one of them chances to 
alight upon the green surface of a young asparagus plant 

231 



232 



FARM FRIENDS AND FARM FOES 



wet with dew or rain, it sends out a germinating tube that 
penetrates the outer skin, generally through a breathing 
pore, and starts a growth of fungus threads or mycelium 
inside. These threads continue to grow and push in be- 
tween the green cells of the leaf or stem, absorbing nourish- 
ment from them. 

After a short time the early spring mycelium has absorbed 
so much material from the green cells that it is able to de- 
velop a new set of spores. A special growth of the fungus 
threads occurs at certain places just below the outer skin, 





Spore Germinating with Tube 
entering slomata; seen 
from above 



Germinating Tube among 
Cells of Leaf; seen from 
side 



which becomes swollen with light green spots. Soon the 
skin breaks apart and the fungus threads produce great 
numbers of small round spores. The small swollen places 
where these spores are produced are called cecidia (singular, 
cecidium\ and the spores produced in them are called cecid- 
ial spores or spring spores, because they develop in spring. 
These spring spores are scattered broadcast by the wind. 
When one of them chances to alight upon the green surface 
of a moist asparagus plant, it sends out a germinating tube 
that penetrates the tissues in much the same way that the 
germinating tube of the sporidium did at the beginning of 
the season. On the inside the germinating tube continues 
to grow, forming new fungus threads that absorb the life 



THE RUSTS 233 

substance of the previously healthy cells. After a time 
this mycelium is ready to produce spores again, and it 
causes more tiny swellings upon the green surfaces of leaves 
and stems. The skin of the swollen dots soon breaks apart, 
revealing swarms of tiny rust-colored spores. These are 
the uredospores or summer spores. They give the famil- 
iar rusty color to diseased asparagus plants. They are pro- 
duced in untold billions, to be scattered by the wind from 
plant to plant and from field to field. 

When they alight under conditions favorable to growth, 
they start the disease anew. These summer spores are the 
chief means for the general dispersal of the rust. Like 
the spores produced in spring, they are unable to survive 
long in a condition to germinate. 

As autumn comes on, if the asparagus host plant becomes 
weakened from any cause, the mycelium in the leaves and 
stems produces yet a third kind of spores — the black rust or 
winter spores with which our little story began. These 
are called teleutospores : they develop in great numbers in 
swollen pustules, their black color giving this stage the 
name black rust to distinguish it from the orange rust of the 
uredospore stage. 

These two celled teleutospores have comparatively thick 
walls which enable them to survive the winter and start 
the disease anew in the spring. 

To summarize this story of the yearly cycle of the As- 
paragus Rust: — 

1. It winters in the black rust or teleutospore stage. 

2. In spring the teleutospores germinate into secondary 

spores called sporidia. 

3. These sporidia infect asparagus plants and start in 

the tissues of leaf and stem a growth of fungus 
threads or mycelium. 



234 FARM FRIENDS AND FARM FOES 

4. This mycelium soon produces certain swellings or 

pustules called aecidia from which spring spores or 
aecidiospores are developed. 

5. These aecidiospores spread the disease and start more 

mycelium. 

6. In summer the mycelium produces other pustules 

from which the orange-colored summer spores or 
uredospores are developed. 

7. These uredospores spread the disease far and wide, 

starting more mycelium from which more uredo- 
spores are developed. 

8. In autumn the mycelium in the tissues produces black 

pustules from which the winter spores or teleuto- 
spores are developed, thus completing the yearly 
cycle. 

Even in a slightly infested asparagus field there are mil- 
lions of teleutospores each spring. If each of these devel- 
ops eight sporidia, there are of course enormous numbers of 
the latter produced. These sporidia are short-lived, how- 
ever, and each must soon find a living asparagus plant if it 
is to start the disease anew. In established fields the 
asparagus is cut and carried off almost as soon as it comes 
up. Consequently, there is little chance for the rust to get 
a foothold there. The asparagus plants upon which the 
disease grows in spring are generally chance seedlings in 
neglected corners or those newly planted fields in which 
cutting has not been begun. It is important, therefore, to 
destroy wild asparagus plants, for they help to tide the 
disease over the weeks of spring. 

Clover Rust 

The Clover Rust is similar in its yearly history to the 
Asparagus Rust. It has the same three kinds of spores 






THE RUSTS 



235 



succeeding one another, and is found upon both red and 
white clovers. It is a widespread disease, but seldom does 
serious injury. 

Another closely related fungus is Alfalfa Rust, but this 
as a rule causes only a minor injury. The pustules showing 
the summer spores are likely to be found upon alfalfa leaves 
at any time in summer. 

The Rose Rust is still another species having a life story 
similar to that of the Asparagus Rust. It is very frequently 
found upon the leaves and stems of roses. Other rusts 
occasionally occur upon beans and beets. 

Wheat Stem Rust 

The Asparagus Rust is typical of the rusts that pass their 
various stages upon one host. There are many others, how- 
ever, in which the fungus develops part of the year upon 
another host, so that the life history may seem even more 
complex than that of the Asparagus Rust. 

The Stem Rust of Wheat is a good example of a rust that 
lives upon two hosts. Most people in regions where wheat 
is grown are familiar with the slender black spots on the 
leaves and stems of ripened wheat. Under a lens these are 
readily seen to consist of teleutospores, similar to the teleu- 
tospores of the Asparagus Rust. They serve as the winter 
spores of the Wheat Stem Rust, living through the winter 
wherever the straws may be. 

In spring the teleutospores germinate by sending out 
tubes, and these tubes in turn give rise to secondary spores 
called sporidia exactly as in the case of the Asparagus Rust. 

These sporidia are blown about by the wind. If one 
chances to light upon a moist barberry leaf, it germinates 
and sends its fungus thread through a breathing pore into 



236 FARM FRIENDS AND FARM FOES 

the tissues of the leaf. Here it develops into a mycelium 
that soon produces swollen orange-colored pustules, often 
called cluster cups. In these pustules the mycelium 
develops aecidiospores or spring spores which in turn are 
blown through the air by the wind. This is often called 
the cluster-cup stage of the rust. 

Some of the aecidio spores are likely to find lodgment 
upon the leaves or stalks of wheat plants. When moisture 
from dew or rain is present, these will germinate and start 
a growth of mycelium in the tissues. This mycelium will 
soon produce a crop of rust-colored uredospores or summer 
spores which scatter through the wheat fields and spread 
the disease rapidly. This process continues through most 
of the summer, and consequently this is the stage in which 
the most damage is done by the rust fungus. 

Finally, as the wheat matures the mycelium in the tissues 
gives rise to the black rust or teleutospore stage. In this 
condition it passes the winter. 

Yearly Cycle of Wheat Stem Rust 

I. Early Spring. 

a. Teleutospores develop sporidia. 
b. Sporidia are blown to barberry. 

c. Sporidia develop mycelium in barberry leaf. 
II. Late Spring. 

d. Mycelium in barberry leaf develops aecidiospores. 
e. ^Ecidiospores are blown to wheat. 

f. yEcidiospores develop mycelium in wheat. 

III. Slimmer. 

g. Mycelium in wheat develops uredospores. 

h. Uredospores are blown to other wheat plants. 

i. Uredospores develop mycelium in these wheat plants. 

IV. Autumn. 

j. Mycelium in these wheat plants develop teleutospores that 
live through the winter. 



THE RUSTS 237 

If you will compare this yearly history of the wheat rust 
with that of the asparagus rust, you will see that the chief 
difference is that the sporidia develop upon another host 
from which the aecidiospores return to the wheat plant. 
This difference is typical of many other rust fungi, and 
special names are given to indicate the group to which the 
various sorts belong : — * 

When the different stages of a rust fungus develop on 
one kind of plant, it is said to be an antoecious species ; ex- 
ample, the Asparagus Rust. 

When the different stages of a rust fungus develop upon 
two or more kinds of plants, it is said to be a Jicteroecio7is 
species; example, the Wheat Stem Rust. 

The stem-rust on wheat and barberry is the typical ex- 
ample of a heteroecious rust. It is interesting because of 
the alternation of host plants and because all three forms 
of spores are present. The Black Stem Rust, however, 
often occurs in regions where barberries are either rare or 
not found at all, and there is no doubt that the fungus can 
live from year to year without going through the cluster- 
cup stage on barberry. 

Other Grain Rusts 

There are other rusts of grain even more destructive 
than the Wheat Stem Rust. The Orange Leaf Rust of 
Wheat is perhaps the worst of these. Technically it is 
called Puccinia rubigo-vera. It is believed by good au- 
thorities to be the most abundant of all grain rusts in the 
United States. The uredospore form is the one generally 
present, and in the South at least the fungus can live 
through the year with no other spores present. Teleuto- 
spores have been found, but the aecidium stage is unknown. 



238 FARM FRIENDS AND FARM FOES 

The Crown Rust or Orange Leaf Rust of oats is an 
abundant and widespread disease. Technically it is known 
as Puccinia coronata. It has a life history very simi- 
lar to that of the Black Stem Rust, the spring spores or 
aecidiospores being developed upon buckthorn instead of 
barberry. There seems little doubt, however, that the 
fungus can pass through the year in the absence of this 
aecidium stage. 

Serious injury by the Rust of Indian Corn is only rarely 
reported, although the fungus is very common. It appears 
on the leaves in brownish pustules of uredospores that 
develop during summer. They are followed later in the 
season by blackish teleutospores which live over winter 
to start the disease anew in spring. This fungus is known 
as Puccinia Sorsrhi. 



Cedar and Apple Rust 

Another good example of a hetercecious rust is the one 
that causes the " cedar apples " so often found on cedar 
trees. These are curious little orange-colored balls that 
occur along the twigs. In autumn and winter they have 
smooth, rounded surfaces, but in spring they send out curi- 
ous jelly-like masses about half an inch long. The teleu- 
tospores germinate by sending out tubes that give rise to 
secondary spores or sporidia. These sporidia are blown 
about by the wind : such as fall on moist leaves of apple, 
quince, or June-berry are likely to germinate and start a 
growth of mycelium within the leaf. 

This mycelium soon gives rise to swollen pustules called 
cluster cups or aecidia. In these millions of brownish 
aecidiospores are developed. These are blown about by 
the wind, and such of them as chance to light upon moist 



THE RUSTS 239 

cedar branches germinate and start a growth of mycelium 
in them. There appear to be no uredospores and no 
spreading of the disease to other apple trees by the aecidio- 
spores. 

Consequently, in this case of the Cedar Apple and Apple 
Rust we have but two distinct forms instead of the three 
in the case of the Black Stem Rust. 

Thus : — 

1 . Cedar Apples on Cedar. 

Teleutospores develop sporidia to go to apple leaves. 

2. Apple Rust. 

A. Sporidia cause mycelium that produces oecidia 
containing secidiospores. 

B. yEcidiospores go to cedar trees to develop cedar 
apples. 

The mycelium in the cedar trees is perennial, living 
from year to year and producing each season new cedar 
apples to send out sporidia. Consequently, the destruction 
of the cedar trees is helpful in preventing the development 
of the Apple Rust. 

Other Rusts 

The Orange Rust of blackberries, dewberries, and rasp- 
berries is one of the most conspicuous and widespread 
members of the family. It affects both wild and cultivated 
plants and is found wherever these fruits grow. The con- 
spicuous orange-colored aecidiospores appear in spring and 
early summer, and are followed later by a crop of uredo- 
spores, and these in turn by the teleutospores. The 
prompt burning of all infested canes is very desirable. 

A characteristic leaf rust, known technically as Puccinia 
Pruni, commonly affects plums, peach, and other stone 



240 FARM FRIENDS AND FARM FOES 

fruits. It is seldom seriously destructive. The only spore- 
forms known are the summer spores and the teleutospores, 
both being of the brown color so general in the rusts. 

During the last quarter of the nineteenth century the 
Hollyhock Rust was very destructive in the United States. 
It is still a pest, but less so than formerly when it caused 
the culture of hollyhocks to be almost abandoned. There 
is good reason to hope that resistant strains of Hollyhocks 
will soon be developed. 

The Hollyhock Rust appears as brownish pustules on 
the under surface of the leaves. These contain an abun- 
dance of two-celled teleutospores, and it is an interesting 
fact that in this form of rust fungus this seems to be the 
only form of spore that occurs. The teleutospores are 
also remarkable for their ability to germinate at once instead 
of resting through the winter as do most of the teleutospores. 
Consequently, in this case the teleutospores are both sum- 
mer spores and winter spores. The gathering and burning 
of affected leaves is a helpful remedial measure. 



OBSERVATIONS FOR PUPILS 
Rusts 

i. Which of the following rusts do you find in your neighborhood? — 

Apple Rust Hollyhock Rust 

Asparagus Rust Oat Crown Rust 

Bean Rust Plum Rust 

Beet Rust Raspberry Rust 

Clover Rust Wheat Leaf Rust 

Corn Rust Wheat Stem Rust 

2. Set aside a page of your booklet for three of the most important 
of these rusts, and write a brief account of your observations upon each. 



THE RUSTS 241 

Perhaps this outline will help : — 

The name of the disease. 

Its abundance and the amount of damage it does. 

The parts of the host plant most affected. 

How it passes the winter. 

The preventive measures used against it in your neighborhood. 

3. Press a few leaves or stalks showing each of the rusts common in 
your locality. Mount them on pages of your booklet. 

4. Read the discussion of Grain Rusts in Farmers 1 Bulletin 219. 



CHAPTER XXII 

The Ascospore and Other Fungi 

A number of parasitic fungi are classified together in a 
group called Ascomycetes because the principal spores are 
developed in special tubular spore cases called asci ; these 
spores are called ascosporcs. They often serve as a means 
by which the fungus passes through the winter; so they 
are sometimes spoken of as winter spores. The fungus may 
also develop more temporary spores which are often spoken 
of as conidiosporcs or summer spores. 

Black Knot 

Most schoolboys have seen the branches of plum and 
cherry trees distorted by a black, knotty growth, having 
the appearance of the picture on the opposite page. Wild 
cherry trees very commonly show the injury, which is pro- 
duced by the fungous disease known as the Black Knot. 
The knots are caused by the growth of a parasitic fungus 
in the twigs or larger branches. They first appear as 
swollen places on the bark. These enlarge and cause 
irregular cracks which are characteristic of the disease. 
Finally the whole circumference of the twig may be affected 
so that the part beyond soon dies. 

During warm weather vast numbers of summer spores 
are produced upon the bark of the knots. These give the 
affected part of the twig a soft, velvety surface of a dark 
olive color. These spores are blown from place to place. 

242 






THE ASCOSPORE AND OTHER FUNGI 



243 



Those that fall upon green and tender bark are likely to 
germinate and start the disease again. 

As cold weather approaches, the tissues of the outer bark 
become much harder, with many little cavities inside. The 
fungus produces within these cavities 
spores that germinate the following 
spring and start the disease anew. 

The Black Knot affects most varie- 
ties of plum and cherry trees, both 
wild and cultivated, and the spores 
are easily carried from one sort of 
tree to another. Consequently, it is 
important that in any locality all 
traces of the fungus should be ex- 
terminated. The cutting down of 
worthless trees and the pruning away 
of diseased branches are the first 
steps in the control of Black Knot. 

The cutting out of the injury as 
soon as it appears and spraying with fungicides will also 
help to control it. 




Black Knot on Wild 

Cherry; winter 

condition 



Peach Leaf Curl 

Peach Leaf Curl is the name applied to a malady 
that often affects the twigs and leaves of peach trees. It 
causes the leaves to swell and curl soon after they expand 
in spring, giving them an abnormal appearance that is at 
once recognized as due to a diseased condition. The threads 
of the fungus penetrate between the cells, growing rapidly 
and causing a swelling of the tissues. The injured leaves 
fall off in the spring or early summer. The twigs affected 
also become swollen and distorted. Sometimes the disease 
is confined to a branch or two, but frequently it involves 



244 FARM FRIENDS AND FARM FOES 

the foliage of the whole tree. In such cases the young 
peaches are likely to drop off, and the crop be thus de- 
stroyed. A new set of leaves will be put forth, but of course 
the tree will be unable to produce the same season another 
crop of blossoms and young fruit. 

Fortunately this disease is readily prevented by spraying 
with fungicides. Winter treatment with Bordeaux mixture 
or the lime-sulphur wash is an effective remedy. This is 
believed to be due to the fact that the spores of the fungus 
pass the winter chiefly on the bark and buds of the trees, 
so that they are killed by the fungicide. 

Plum Pockets 

The Peach Leaf Curl is due to the growth of a parasitic 
fungus that belongs to the genus Exoascus. The fungi of 
this genus cause abnormal growths of the plants they in- 
fest. The curious "witches brooms " often seen upon birch 
and other trees are due to these parasites. So, also, are the 
strangely swollen plums often seen upon the plum trees and 
commonly called Plum Pockets. 

Young plums are generally affected by the Plum-pocket 
disease. They become swollen, and when cut open are 
seen to be hollow, with no pit. After a time they are likely 
to be covered with a powder composed of the microscopic 
spores of the fungus. These spores are widely scattered 
by wind and rain, and presumably infest other trees, though 
just how this is done is not now known. 

It is known, however, that the threads of the fungus live 
from year to year in the twigs and reach the young fruits 
by growing through the blossom or fruit stalks. When a 
branch is once infested, it bears the Plum Pockets year after 
year, and all new twigs sent out by it beyond the point of 



THE ASCOSPORE AND OTHER FUNGI 



245 



infection do likewise. Consequently it is evident that the 
threads of the fungus grow along with the new growth of 
the branch. The best remedy is to cut the branch off, some- 
what below the point of infection, thus removing the dis- 
eased tissues. 



Apple Scab and Pear Scab 

The Apple Scab is one of the most familiar fungous 
diseases. It appears as black spots, upon the surface of the 
apple, and also 
upon the leaves. 
The spores of 
the fungus that 
causes the dis- 
ease are pro- 
duced in great 
abundance on 
these blackened 
spots. They are 
scattered far and 
wide by wind and 
rain. Those that 
lodge upon the leaves or fruits of apple trees germinate 
during moist weather by sending out little tubes and thus 
start the disease anew. 

The growing portion of the fungus consists of brown- 
ish cells. After a time the cells multiply and push out- 
ward, exposing a surface in which the small oval spores 
develop. These spores live through the winter on the 
bark, twigs, and stored apples, as well as on the fallen 
leaves and fruit. 

The Apple Scab fungus not only causes the apples to 
appear unsightly and injures them for food, but it also pre- 




AprLE Scab 



246 FARM FRIENDS AND FARM FOES 

vents them from growing to as large a size as they would 
if not affected. The extent of this dwarfing is illustrated 
in the figure below. The disease may be prevented by 
spraying with fungicides, the self-boiled lime-sulphur wash 
being one of the best for this purpose. 





DWARFED BY 
APPLE SCAB 

A closely related fungus causes the Pear Scab, which is 
often destructive to certain varieties of pears. Its life his- 
tory and control are practically the same as the Apple 
Scab. 

Bitter Rot of Apple 

This disease causes losses of millions of dollars in the 
United States almost every year. It is generally noticed 
upon the fruit, especially as it approaches full size. Small 
brownish spots may be seen at first ; these gradually en- 
large and commonly spread over much of the apple, caus- 
ing it to fall. Many of the smaller fruits, however, re- 
main upon the tree, shriveling to a mummified condi- 
tion, in which they may hang to the twigs until the next 
spring. 

After the mycelium of the fungus has been growing in 
the fruit tissues for a time, it develops upon the surface 
characteristic blackish pustules in which great numbers of 



THE ASCOSPORE AND OTHER FUNGI 



247 



spores are produced. These are scattered by wind and rain 
and serve to spread the disease to new fruits. The myce- 
lium gives a bitter taste to the parts of the apple near the 
decayed spot. 

This fungus is also 
able to develop upon 
the bark of apple 
trees, where it pro- 
duces dead blotches 
called cankers. The 
fungus apparently 
passes the winter both 
in these cankers and 
in the mummied fruits, 
from which new crops 
of spores are pro- 
duced in spring or 
early summer. 

The destruction of 
mummied and fallen 
fruits, cutting out and 
burning all canker 
spots, and spraying 

with fungicides are the means by which this disease may 
be controlled. 




Apples affected by Bitter Rot 



Brown Rot of Stone Fruits 

The Brown Rot of peaches, plums, and cherries is one 
of the most destructive diseases affecting fruits. It is the 
commonest cause of the rotting of peaches or plums both 
upon the tree before or during ripening, and also in the 
baskets after picking. Its life history is similar to that of 
the other fungi that cause plant diseases. The tiny spores 



248 



FARM FRIENDS AND FARM FOES 




Brown Rot Spores 

Developing 

Magnified 



blown upon the damp fruit send out their germinating 
tubes into the tissues where they grow, branching in all 
directions. These branches absorb the cell contents. In 

this way the green tissues are broken 
down, the light green color is turned 
to brown, and the so-called rot ap- 
pears. On the outside, the fruit first 
turns brown in one or two places, then 
more and more of the surface appears 
affected, until finally the whole surface 
shows the injury. 

Soon after the fruit has thus be- 
come discolored, it is likely to show 
a curious velvety coating — more or 
less grayish in color — that is made 
up of millions of tiny spores. They 
are produced by the threads of mycelium that have been 
developing amid the tissues of the fruit. Under the micro- 
scope they are easily seen to resemble the figures below. 

These spores are blown everywhere 
by the wind and serve to spread the 
disease very rapidly. A single affected 
fruit may furnish millions of spores for 
the wind to sow broadcast over the 
surrounding country. 

Unless the diseased fruits are re- 
moved, many of them remain upon the 
tree. They shrivel slowly into dry 
and mummied fruits inside which the 
threads of mycelium develop into 
blackish bunches that correspond in a 
way to winter spores and enable the 
fungus to survive the winter, and to produce a new crop 




Brown Rot 
a, spores ; b, spores ger- 
minating ; magnified 



THE ASCOSPORE AND OTHER FUNGI 249 

of spores in spring. These are likely to develop in the 
tissues of the buds, blossoms, and young twigs, often caus- 
ing serious damage. 

Sometimes a curious mushroom stage of the fungus de- 
velops in connection with the mummied fruits upon the 
ground. Great numbers of tiny mushroom-like objects 
develop from the mycelium. In these the winter spores 
or ascospores are produced. Apparently this stage is not 
generally present, and is not necessary to the yearly cycle 
of the fungus. 

Evidently one of the chief preventive measures with 
this disease is the gathering of all the mummied fruits in 
winter. By doing this, by thinning the fruit, and by spray- 
ing with self-boiled lime-sulphur wash, most of the injury 
may be avoided. 

Pear Leaf Blight 

The foliage of pear and quince trees often becomes 
spotted with brown in summer, and the spotting sometimes 
is so extensive that the leaves turn brown and fall off. 
When this occurs over the whole tree and is not at first 
confined to a single branch, it is generally caused by a fungus 
that attacks the leaves early in the season and continues 
to develop until the end of summer, causing the disease 
known as the Pear Leaf Blight. This fungus is a distinct 
species of parasitic plant which at first causes small reddish 
spots to appear upon the leaves. These spots gradually 
grow larger and turn brown and often cause the whole leaf 
to become brown and dead. The fungus also develops 
upon the fruit, causing it to crack open. Fortunately this 
disease may be almost entirely prevented by spraying with 
fungicides. 



250 FARM FRIENDS AND FARM FOES 

Strawberry Leaf Spot 

Every one who grows strawberries has noticed the brown 
or reddish spots that appear upon the leaves, especially 
late in summer. These are due to a fungous disease called 
the Strawberry Leaf Spot. When the spots first appear, 
they may be seen on the upper side of the leaf as small 
dots of a purple or reddish color. They grow larger from 
day to day; the central portions become brown in color, 
while the margins retain their purple hue. The fungus 
threads within the cells of the leaf generally affect a cir- 
cular area, but frequently two or more centers of disease 
will be sufficiently near each other to run together and 
produce a large discolored blotch. Sometimes practi- 
cally the whole leaf will be destroyed. The effect of the 
disease upon the plant is to dwarf its growth and lessen 
the fruit crop produced the succeeding year. 

The Strawberry Leaf Blight may be prevented to a con- 
siderable extent by spraying with the Bordeaux mixture. 
Of course this cannot be applied while the berries are on 
the vines. An excellent way to treat fruiting plantations 
is to mow the vines after the berries are gathered, and 
burn the ground over as soon as the leaves are dry. This 
destroys the spores of the fungus and a new crop of leaves 
will soon be produced comparatively free from blight, 
especially if they are sprayed once with the Bordeaux 

mixture. 

The most successful growers of strawberries renew their 
plantations every year, as they find it easier to set out a 
new bed than to clean out an old one. When this method 
is adopted it is seldom necessary to spray to prevent the 
Leaf Spot. 



THE ASCOSPORE AND OTHER FUNGI 



Black Rot of Grapes 



2 5i 



The Black Rot of grapes is one of the most destructive 
plant diseases. It often causes the loss of a large part of 
the crop in many vineyard regions and is generally recognized 
as a dangerous enemy. The disease is caused by a fungus 
that passes the winter in mummied grapes and is believed 
to start in spring from ascospores developed in them. It 
appears in spring or early summer on young leaves and 
branches, producing a brown discoloration. Later it shows 
on the green grapes as brownish spots that spread over 
the whole surface, finally producing a blackened fruit that 
is appropriately described as affected by Black Rot 

On the surface of these diseased grapes enormous numbers 
of summer spores are developed. These are scattered 
through the vineyard by wind and rain. Whenever one 
rests upon a moist grape, it is likely to start a new disease 
spot. In this way the disease may spread very rapidly 
and cause great loss. 

Clean culture and the destruction of dried grapes that 
carry the fungus through the winter are desirable preven- 
tive measures. Spraying with Bordeaux mixture has re- 
peatedly been shown to be an efficient remedy. 

Cotton Wilt 

Among the numerous enemies of cotton that have be- 
come seriously destructive during recent years, the Wilt 
Disease is especially notable. It occurs over a large part 
of the cotton-growing region in the Southern states. The 
affected plants are commonly stunted in their growth for 
some time before they finally wilt as if from lack of water. 
This is in fact the case, because the channels through 



252 



FARM FRIENDS AND FARM FOES 



which the water reaches the leaves are clogged by the 
growth of the parasitic mycelium. 

The careful studies of several botanists show that the 
fungus which causes the disease is commonly present in the 
soil of cotton fields, where it is able to live long periods 
as a saprophyte — getting the materials of growth from 
decaying matter in the soil. When cotton is planted, how- 
ever, it commonly becomes a parasite by invading the 
tissues of the plants. The same or a very similar fungus 
causes a wilt disease in watermelons and in the cowpea. 

The only successful method of preventing this disease 
now known is that of planting varieties that can resist 
its attack. Much progress has been made in the develop- 
ment of such varieties, and there is reason to believe that 
still greater progress will be made in the near future. 

The Powdery Mildews 

From midsummer until autumn one can find curious 
whitish patches upon the leaves of a great variety of trees, 
shrubs, and herbaceous plants. In some cases there are 
but small spots of white upon the green background of the 
leaf blade, while in others the whole surface may be whit- 
ened and more or less powdery in appearance. As autumn 
approaches tiny brownish or blackish spots appear upon 
the whitened part. Such whitened leaves are very com- 
mon upon lilacs, roses, willows, red maples, hardy phloxes, 
and many other plants. They are especially likely to 
be found on leaves growing in the shade. Such leaves 
are probably affected by some form of those parasitic 
fungi called Powdery Mildews. These are among the'most 
characteristic of the ascospore fungi, and form a very dis- 
tinctive family. 



THE ASCOSPORE AND OTHER FUNGI 253 

If you will look through a lens or the lower power of a 
compound microscope at one of the leaves thus affected, 
you will see that the whitish appearance is due to vast 
numbers of tiny threads that run over the surface of the 
leaf, interlacing in a most interesting fashion. You will 
find that the brownish or blackish dots are well-developed 
spore cases — technically called perithecia — often having 
curious projections from the outer wall. You can probably 
see these cases in all stages of growth, from the young 
whitish ones to the mature blackish ones. 

If you place a few of the well-developed spore cases on 
a glass slide in water, cover with another piece of glass, 
and crush the walls, you will see the spores come out. 
These spores are inclosed in smaller sacklike cases — the 
asci. 

When the leaves fall in autumn, these black spore cases 
fall with them, and the spores inside remain over winter to 
start the disease anew in spring. For this reason they are 
often called the winter spores. 

In spring or early summer the fungus threads get 
started on the leaves. Unlike many other fungi, the 
threads do not grow in or between the tissue cells of the 
leaf, but they remain upon the outside and send curious 
suckerlike projections in through the breathing pores of 
the leaf to absorb food from the cells. 

During summer, especially before the development of 
the winter spore cases, the affected leaves often have a 
powdery appearance. This is due to the development of 
millions of tiny white spores. Certain threads of the my- 
celium grow out at right angles to the surface of the leaf, 
and on their ends produce spores that serve for the spread 
of the fungus during the warm months. These are called 
summer spores or couidia. 



254 



FARM FRIENDS AND FARM FOES 



A great many different kinds of powdery mildews are 
found upon wild and cultivated plants. One of the most 
abundant of these is the Cherry Powdery Mildew, which 
occurs also on apples and other fruits. It is especially de- 
structive to young trees in nursery rows. The Gooseberry 
Powdery Mildew is another widespread and destructive 
disease. It is especially likely to attack English varieties 
of gooseberries when grown in America. The Grape 
Powdery Mildew is also more or less injurious over most 
of the United States, and the Powdery Mildew of the Bean 
is likewise widely injurious. 

The powdery mildews live externally upon the leaves 
and stalks of plants more than is the case with most para- 
sitic fungi. Hence we would expect that they could be 
easily prevented by spraying with fungicides, and this is 
true. These mildews are checked by applying almost any 
of the fungicides. 

Other Fungous Diseases 

A considerable number of fungous diseases are due to 
parasites, the complete life histories of which have not yet 
been discovered. Such fungi are commonly classified 
under the heading Fungi Impetfecti or Imperfect Fungi. 
The imperfection, however, is found chiefly in our lack of 
knowledge. As the diseases are more carefully investi- 
gated, the parasites are being transferred to the various 
groups to which they belong. 

The Potato Scab is one of the most important of these 
diseases. It is caused by an inconspicuous fungus that in 
freshly dug potatoes may often be seen as a coating of fine 
white threads over the scabby surface. The disease occa- 
sionally occurs upon beets and other root crops. Spores 
are produced among these threads. It is now well estab- 



THE ASCOSPORE AND OTHER FUNGI 



255 



lished that on potatoes this disease may be prevented by 
rotation of crops and soaking the tubers to be planted in a 
solution of formalin of the strength of one ounce to two 
gallons of water. 

From the viewpoint of geographical distribution, the Early 
Blight of the Potato seems even 
more important than the Late 
Blight. The former is distrib- 
uted throughout the United 
States, while the latter is chiefly 
destructive in New York and 
New England. The Early 
Blight appears about the time 
the plants blossom, showing as 
small brown spots scattered over 
the leaves. Sometimes the spots 
enlarge and run together into 
blotches. The whole plant is 
often killed long before its time, 
so that the tubers in affected 
fields are small, though there is 
no rotting effect on account 
of this disease. Fortunately, 
spraying with Bordeaux mixture is an efficient preventive. 

The Anthracnose of Beans is another widespread and im- 
portant disease. It is familiar to most people who have 
attempted to grow string beans, because the reddish brown 
spots upon the pods are too conspicuous to be overlooked. 
Sometimes the disease is called the Pod Spot. Such in- 
jured pods are generally worthless, and the whole crop is 
often ruined in wet seasons, for moisture is an important 
factor in the development of the parasite. 

When the pods are seriously affected by the fungus, 




Potato Leaf affected by 
Early Blight 



256 FARM FRIENDS AND FARM FOES 

the beans inside are also liable to be affected. If such 
beans are planted, they are liable to start the disease in the 
new crop. Consequently, the selection of seed from fields 
or pods in which the fungus is not present is the most 
promising preventive measure. It is also desirable to burn 
infested vines after harvesting as well as to rotate the crop 
and select for it high, well-drained land. 

The Cotton Anthracnose is an important disease in 
many Southern states. It occurs especially upon the bolls, 
but also affects other parts of the plant. The injury to 
the bolls is suggestive of that upon bean pods, and the af- 
fected bolls are likely to result in infected seed. 

The Anthracnose of Raspberry and Blackberry is an- 
other widespread disease. It produces characteristic red- 
dish purple spots upon the young canes in spring and sum- 
mer. The centers of the spots later become grayish white, 
and the spots enlarge, often running together and forming 
blotches. The spores are developed in dotlike elevations. 

The best means of controlling this malady are found in 
the removal of affected canes, frequent rotation of the 
plantation, and spraying with fungicides. The self-boiled 
lime-sulphur wash would seem worthy of trial in an ex- 
perimental way. 

Still another Anthracnose affects green grapes, producing 
a characteristic injury that is sometimes called Bird's-eye 
Rot. It occurs upon leaves and branches as well as the 
fruit, but is most destructive to the latter. The destruc- 
tion of diseased portions is an important preventive measure. 

Clubroot of Cabbage 

This disease is caused by a low form of parasitic fungus 
that is classed with the group of Slime Molds rather than 






THE ASCOSPORE AND OTHER FUNGI 257 

the Imperfect Fungi where the diseases discussed in the 
last few pages are classified. The fungus causes strange 
malformations of the roots of cabbage, cauliflower, and 
other wild and cultivated members of the mustard family. 
It reproduces by spores and is especially likely to develop 
in acid soils. Consequently liberal applications of lime 
and rotation of crops are helpful methods of preventing in- 
jury. Especial care should be taken not to throw diseased 
roots upon the compost heap. It is better to burn them. 

OBSERVATIONS FOR PUPILS 
Black Knot 

1. Is the Black Knot abundant in your locality ? Does it occur 
upon wild cherry trees ? If so, upon what kind of wild cherries is it 
most abundant — the choke cherry, the wild black cherry, or the wild 
red cherry ? 

2. Notice the difference between the dry or winter condition and 
the velvety or summer condition of the knots. Feel the velvety coating. 

3. If a microscope is available, look at the spores from the velvety 
surface by means of a high power. 

4. What preventive measures against Black Knot are used in your 
locality ? Is there a law in your state requiring property owners to 
destroy the knots ? 

5. Do you think that the presence of this disease along roads and 
fences and in dooryards is a reflection upon the efficiency of your school 
as an agent for the common good ? If so, why not organize a campaign 
of extermination against the Black Knot ? 

6. rtas one man a right to allow the spores of Black Knot to 
develop on his trees to be blown to the trees of his neighbors ? 

7. Make a careful sketch of a twig, showing Black Knot, for your 
booklet. 

Powdery Mildews 

1. Look at leaves of lilac, willow, and other plants to find those 
affected by the whitish covering of the Powdery Mildews. 

2. Bring such leaves to school and study them as directed on pages 



258 FARM FRIENDS AND FARM FOES 

253-254. See if you can distinguish the summer spores and the winter 
spore cases. 

3. Make a list of the Powdery Mildew diseases that you know to 
occur in your locality. 

4. Make a list of remedies that are used in your locality to prevent 
injury by these diseases. 

5. Make sketches of the fungi as seen through the microscope, also 
of leaves showing spots where the fungus is present. 

Cotton Diseases 

1. Learn what diseases are most destructive to cotton in your region. 
Collect specimens. 

2. Read such of these references as your teacher directs : — 

Farmers' Bulletins 302, 333. 

Other Diseases 

1. How many of the following diseases are you able to find in your 

locality ? — 

Peach Leaf Curl. 

Plum Pockets. 

Strawberry Leaf Blight. 

Brown Rot of Stone Fruits. 

Black Rot of Grapes. 

Bitter Rot of Apples. 

Apple Scab. 

Pear Leaf Blight. 

2. Write a short account of your observations upon three or more of 
these diseases. This outline may help : — 

The abundance of the disease. 

The parts of the host affected : whether leaf, fruit, or bark. 

How diseased leaves or fruits look. 

How the fungus passes the winter. 

Preventive measures. 

3. Make sketches showing the characteristic appearance of each 
disease you write about. 



CHAPTER XXIII 
Bacterial Diseases of Plants 

The microscopic one-celled plants called Bacteria or 
Microbes are now known to be the cause of some of the 
most destructive plant diseases. In a way the life history 
of these bacteria is simpler than that of many of the fungi 
affecting growing crops. The bacteria multiply chiefly by 
a simple division of the cells, each single cell dividing into 
two cells. This is a very rapid process, however, so that 
when once within the tissues of a plant the disease-pro- 
ducing microbes spread very quickly. Consequently, these 
diseases are often called Blights. Another appropriate 
name for some of them is Bacteriosis. 

Pear Blight 

One of the best-known and most characteristic of these 
bacterial diseases is the Fire Blight of the Pear, Quince, 
and Apple. The leaves on the branches affected by this 
malady suddenly turn black as if injured by fire and hang 
upon the twigs in this blighted condition for some time. 

This Blight affects pear trees much more than apple 
trees and is the most serious obstacle in the way of suc- 
cessful pear culture. It is very generally known simply 
as the Pear Blight. It has been carefully studied by many 
scientists, so that the characteristics of the disease are well 
known. The microbe causing the malady was named 
Bacillus amylivorus by Professor T. J. Bur rill of Illinois. 

259 



260 



FARM FRIENDS AND FARM FOES 



Drops of viscid liquid are commonly found along the 
margin of the diseased areas of the bark. These are 
swarming with the germs of the Bacillus. Bees and other 
insects are attracted to these drops, sucking them up and 
getting myriads of microbes upon their feet and mouth 
parts. 

Many bacteria multiply rapidly in sweet, jelly like liquids. 
Such a liquid is found in the nectar cup at the base of the 
pear blossom, and to a less extent on the end of the pistil 

of the same flower. Should a bee 
visit a diseased tree and get some 
of the blight microbes upon its 
feet or mouth parts, and then visit 
the blossoms of a healthy tree, some 
of these germs would probably be 
introduced upon the nectar of the 
latter. 

CLAW FROM BEE'S FOOT When thllS P laCed in * POMtiOll 

with blight bacteria favorable to growth, the bacteria 

to show the relative mult i ply rapidly, and follow down 
size: Highly Magnified ■, 

through the stalk of the flower to 

the twig. Here they continue to develop, and soon may 

spread downward through the branch. As far as they go 

they kill the tissues, causing blossoms, leaves, and twigs 

to turn black. 

The germs may also be introduced to new trees through 

breaks in the bark or by the gnawings of insects. The 

disease is more severe in trees that grow rapidly than in 

those that grow slowly. Consequently cultural methods 

that induce rapid growth are to be avoided. The prompt 

cutting off and burning of all affected branches, taking 

care that the germs are not distributed by saw, knife, or 

shears, is the most effectual remedy. 




BACTERIAL DISEASES OF PLANTS 261 

Crown Gall Disease 

It is now pretty well established that the widespread 
disease of fruit trees called Crown Gall is caused by bac- 
teria. This has recently become one of the most destruc- 
tive maladies of trees, having been widely distributed 
through nursery stock before its real nature was discovered. 
This disease appears in spring as an abnormal growth upon 
the roots of apple, pear, peach, and other trees, as well as 
those of blackberries and raspberries and various herba- 
ceous plants. The growth continues through the season, 
often forming large galls of varied shapes. Ordinarily 
the growth ceases at the end of the first season, and the 
gall later decays and disintegrates. New galls are likely 
to appear the next season on other roots in large num- 
bers, damaging the root system so badly that the tree may 
finally die. 

It is easy to see how readily soil could be inoculated with 
crown-gall germs. If a diseased tree is planted and later 
dug up, it is probable that millions of the spores will remain 
in the ground. Consequently great care should be taken 
not to set diseased plants, and if possible to get plants from 
nurseries where crown gall is not present. 

Cabbage Rot 

The Cabbage Rot is another bacterial disease that has 
been carefully studied by several scientists in widely sep- 
arated regions. The malady is especially destructive to 
cabbages, often ruining large fields. It also attacks cauli- 
flowers, turnips, rutabagas, and various other plants of the 
mustard family. It has been found on Charlock, a weed 
belonging to this family, and probably occurs upon other 
species. 



262 FARM FRIENDS AND FARM FOES 

The fact that the Cabbage Rot is caused by a bacterial 
germ has been abundantly demonstrated. If you look 
at cabbage leaves during a season of damp weather, you 
will probably see a row of water drops along the margin 
of each leaf. These have come out from small pores, 
extending from the margin to the veins of the leaf. The 
leaves are constantly giving off surplus water through 
the pores ; in dry weather the water evaporates as it 
emerges, but in moist weather it remains to form the water 
drop. 

When one of the tiny bacteria carried in the air by the 
wind happens to lodge in one of these water drops, it begins 
to multiply, and soon develops in such numbers that the 
bacteria enter the leaf through the water pore. Once in- 
side, they travel down the veins, causing injury as they 
go, until they reach the main stalk. They follow the large 
channels in this stalk, and sometimes permeate the whole 
head by pushing along through the system of veins. 

The injury done by these myriads of microbes checks 
the growth of the plant and finally kills it. The germs of 
other microbes soon enter the injured tissues and cause a 
vile-smelling rot which effectually completes the work of 
destruction. 

While the Cabbage Rot Bacterium is able to invade 
healthy plants through the pores, it is often introduced 
also by the bites of insects. If an insect is feeding upon 
a diseased cabbage, its mouth parts are likely to be more 
or less covered with the disease germs. If it then bites a 
healthy plant, some of these germs will enter the tissues 
of the latter, and the malady be started anew. 

The disease has proved very difficult to overcome. 
Crop rotation and clean culture are helpful, but they are 
by no means always effective. The selection of healthy 



BACTERIAL DISEASES OF PLANTS 263 

plants from the seed bed is important. Warm, moist 
weather is favorable to the development of the malady. 
Duggar advises soaking the seed for twenty minutes in 
formalin solution, one part to two hundred parts water. 

Other Bacterial Diseases 

The Bacteriosis or Blight of the Bean and related plants 
is another destructive disease. It affects especially the 
pods, producing soft spots with a characteristic water- 
soaked appearance. More rarely it attacks the stems and 
leaves. Apparently the disease may be started through 
infected seeds, so that care to select seeds from blight-free 
fields is desirable. 

The Bacteriosis of melons, cucumbers, and other vines 
is still another destructive malady. The bacteria develop 
in enormous numbers in the water channels of the plants, 
thus preventing water from reaching the leaves, and caus- 
ing the sudden wilting of the latter. Flea beetles, striped 
beetles, and other insects help to carry the microbes from 
plant to plant. 

Corn and celery are both subject to bacterial diseases, 
and cotton bolls are attacked by microbes that cause the 
Cotton Boll Rot. Potatoes, tomatoes, and eggplants are 
the victims of another bacterium that causes injury to 
leaves and tubers or fruits. 

OBSERVATIONS FOR PUPILS 

Pear Blight 

1. Have you ever seen pear trees injured by this disease? 

2. How did it show itself? 

3. Have you seen blighted apple branches? 

4. Read this reference : — 

Pear Blight: Its Cause and Prevention, Yearbook Reprint 500. 



CHAPTER XXIV 
Preventives of Fungous Diseases 

In a general way the methods used to prevent injury by 
fungous diseases come under the head of preventives rather 
than of remedies. Even in cases where an injured part of 
a plant is cut off, the aim is to prevent further spread of the 
disease within the tissues of the plant or to the tissues of 
other plants. When the fungus has once invaded the cells, 
there is little hope of remedy so far as the affected part 
of the host is concerned. In the case of the external 
mycelium of the powdery mildews, however, the fungicide 
may have a direct effect. 

The various fungicides are really preventives rather than 
remedies. They kill the spores or mycelium threads upon 
the outer parts of the plants treated, or they lie in wait to 
kill whatever spores may come to seek entrance to the tis- 
sues. The chemicals of the fungicides do not enter the tis- 
sues of the host to destroy the fungus threads among the cells. 

It is evident that the prevention of the ravages of fun- 
gous diseases is a broad subject. Many ways will readily 
occur to one who thinks of the myriads of parasitic fungi 
and their varied host plants. These ways may all be 
grouped, however, under two general topics :. namely, (i) 
the destruction of the parasite; (2) the prevention of its 
growth upon or within the host. 

Preventive Measures 

Taking up the latter topic first, we find that for many 
fungous diseases the most important method of prevention 

264 



PREVENTIVES OF FUNGOUS DISEASES 265 

lies in the selection of varieties or strains of varieties that 
are able to resist the attacks of the parasite. In the case 
of the grain rusts as well as of many other diseases, this 
seems to be the only practical way of preventing injury. 
It is of the greatest importance that disease-resisting sorts 
be planted of all crops in which there is a variation in this 
ability. Crop growers should always be on the alert to dis- 
cover individual plants that are able to resist the parasites. 
One may thus develop a strain of greatest value. 

Some years ago an asparagus field in one of the central 
Western states was struck by the asparagus rust. In the 
great area of reddened plants, only one stood out green and 
flourishing. Through some peculiarity of its life substance 
it was able to resist the attacks of the fungus. The owner 
had the good sense to see that this plant might be made 
the parent of a resisting race. So he saved the seed, 
selected the most resistant plants that grew from them, and 
in a few years was able to introduce to the trade a valuable 
variety. 

Similar progress has been made in the selection of vari- 
eties of cotton able to withstand the dreaded wilt disease 
for which no remedy is known. 

The selection of disease-resistant plants and the breeding 
of new varieties from them is now occupying the attention 
of many painstaking men. Much progress has already 
been made, and we may soon expect great benefit from their 
labors. 

Another important method of preventing the growth of the 
parasite upon its host is so to isolate the crop that the fun- 
gus may not reach it. In the case of many diseases, the 
spores of which are carried far and wide through the air, 
this is not practicable. Many of the rusts, for example, 
travel great distances on the wind, and thus reach crops 



266 FARM FRIENDS AND FARM FOES 

on new ground. In the case of many other diseases, how- 
ever, the fungus remains in the soil from year to year, and 
unless crop rotation is practiced, each succeeding season 
is likely to show greater damage. This is notably true of 
some of the smut diseases: a garden in which sweet corn 
was grown for many years finally produced few ears that 
were not injured. This fact makes more plain the lesson 
of all good agriculture that a rotation of crops is one of 
the first essentials to success. 

In general, good tillage and fertilization help to prevent 
injury by fungous diseases. Many plants seem better able 
to grow without damage by fungi when they are in a 
vigorous condition. This is not always true, however, for 
the very rapidity of growth in some plants produces condi- 
tions favorable to the development of the parasite. Pear 
trees of quick growth are much more liable to blight than 
those of slower growth, and grains growing vigorously seem 
to be more liable to injury by rusts than those of slower 
growth. 

Sometimes it is possible to exclude the germs of the para- 
sites by mechanical means. The various mildews and rots 
that affect grapes are readily excluded by fastening paper 
bags over the stems soon after the fruit is set. 

In many instances the easiest way to prevent the spores 
of fungi from reaching new hosts is through the direct de- 
struction of the fungus that produces the spores. This is 
obviously a practical method that may be adopted under 
greatly varying conditions. In general it involves clean 
culture and the destruction of refuse materials upon which 
spores may be developed. The plants of many crops may 
continue to produce fungus spores after the fruits are 
gathered, and the burning or deep burying of such plants 
is very desirable. In the case of species of fungi that 



PREVENTIVES OF FUNGOUS DISEASES 267 

alternate from one host to another the. destruction of one 
form may prevent the development of the other. Thus, 
the easiest way to prevent injury by apple rust is to cut 
down the cedar trees on which the infecting spores develop. 
In the case of others, the fungus may develop on wild 
plants and the spores be carried to those cultivated. Thus, 
in fighting black knot in plum and cherry orchards it is 
essential that the infested wild cherry trees in the same 
locality be destroyed. 

Remedial Measures 

The use of fungicides — or substances that kill fungi — 
has recently become the most generally adopted method of 
preventing these diseases. These substances are applied 
to the surface of the soil, stems, foliage, or fruit, where they 
may kill the spores present at the time and may also re- 
main for a considerable period in condition to destroy any 
spores that subsequently alight. 

The various salts of copper are among the most impor- 
tant fungicides. These are used in a great many ways, but 
the most important combination is that of copper sulphate, 
commonly called blue vitriol with lime and water. This 
mixture was first used in Bordeaux, France, to prevent cer- 
tain grape diseases. So it is generally called the Bordeaux 
mixture. It is now the most widely used fungicide and is 
recognized as a sure preventive of many plant maladies. 
The usual formula is : Copper sulphate, 4 pounds ; unslaked 
lime, 4 pounds ; water, 50 gallons. 

The application of Bordeaux mixture to apple trees often 
causes a troublesome russeting of the fruit that lessens the 
value of the crop. On this account, dilute lime-sulphur 
washes are used in its place in many orchards. 

Copper sulphate is also used in simple water solution. 



268 FARM FRIENDS AND FARM FOES 

For spraying dormant trees in winter or early spring, it is 
used at the rate of one pound dissolved in fifty gallons of 
water. For spraying trees in leaf it is used at the rate of 
two ounces dissolved in fifty gallons of water. 

Carbonate of copper is also used as a fungicide. It is 
generally prepared as follows : Three ounces of the car- 
bonate are to be dissolved in three pints of ammonia, the 
whole then being added to a barrel of water. The pow- 
dered carbonate dissolves more readily if it is first made 
into a paste by mixing with water. One advantage of this 
fungicide, which is used for the prevention of apple scab 
and various mildews, is that, being a clear solution, there is 
no clogging of nozzles, as sometimes happens with the Bor- 
deaux mixture. 

Sulphide of potassium or liver of sulphur is sometimes 
used to prevent the mildew on the leaves and fruit of goose- 
berries. Half an ounce is dissolved in two gallons of hot 
water, and the solution when cold is applied to bushes in 
the form of a spray. 

Powdered sulphur, commonly called flowers of sulphur, 
is valuable as a fungicide for some forms of fungi affecting 
plants. It is used in California as a preventive of asparagus 
rust. The fumes that rise from the sulphur on the hot soil 
in sunshine kill the rust spores. 

The lime-sulphur spray used as a remedy for scale in- 
sects is also a fungicide. It has proved one of the best 
remedies for peach-leaf curl, brown rot of stone fruits, apple 
scab, and other diseases. 

Solutions of formalin have been found of great value as 
fungicides in the treatment of potato scab and grain smuts. 
Fortunately, this substance is now taking the place of cor- 
rosive sublimate — a poison too dangerous to use unless 
absolutely necessary. 



PREVENTIVES OF FUNGOUS DISEASES 269 

Combining Insecticides and Fungicides 

In many cases it has been found that a fungicide is also 
of value as an insecticide, and vice versa. In others, it is 
easy to add an insecticide to the fungicide solution, and thus 
prevent both classes of injury by one application. A Bor- 
deaux mixture with arsenate of lead added is the combina- 
tion most frequently used in the past, but it seems likely to 
be displaced by the combination arsenate of lead and the 
lime-sulphur wash. 

" The successful orchardist of the future," writes W, M. 
Scott, " will be the man who, among other things, studies 
the conditions existing on his own farm and sprays his 
trees according to the needs of each variety for the control 
of the particular troubles which occur in his locality. 
The course of treatment best suited for the orchards 
of the Shenandoah Valley of Virginia may not neces- 
sarily give the best results in orchards situated east of 
the Blue Ridge in that state, and again the treatment for 
certain varieties of apples may be different from that re- 
quired for certain other varieties growing in the same 
locality. The course of treatment should be planned not 
only with reference to the diseases to be controlled, but 
also with reference to the probable effect of the fungicide 
upon the fruit and foliage of the variety to be treated. 
The Ben Davis, for example, is so seriously russeted by 
applications of Bordeaux mixture that often most of the 
fruit sprayed with this fungicide is rendered second class. 
In Virginia this variety does not suffer materially from the 
attacks of scab, bitter rot, or other serious fruit diseases, the 
leaf spot which is easily controlled being its chief fungous 
enemy. The Ben Davis in Virginia and in other similar 
situations may therefore be successfully sprayed with a 



270 FARM FRIENDS AND FARM FOES 

weak fungicide which will control the leaf spot, sooty fungus, 
and slight scab infections without injury to the fruit or foli- 
age. The York Imperial is another variety which has no 
serious disease of the fruit, and in addition it is not subject 
to Bordeaux russet, so common on the Ben Davis, but the 
foliage is susceptible to leaf spot and is often badly injured 
by applications of Bordeaux mixture. 

11 On the other hand, the Yellow Newtown is seriously 
subject to the attacks of bitter rot and must be treated with 
a strong fungicide, such as Bordeaux mixture, for the con- 
trol of this disease. The fruit of this variety is susceptible 
to Bordeaux injury, but since such injury is produced only 
by the early applications of the mixture, the treatment may 
be so planned as to avoid it. One of the lime-sulphur 
sprays may be used for the first and second sprayings after 
the petals fall, and Bordeaux mixture for the bitter rot 
treatments which come later. These are the finer points 
to be considered in connection with spraying, and the 
orchardist who gives them due consideration will obtain 
the best results in the production of good fruit." 

The National Department of Agriculture issues bulletins 
giving precise directions for the preparation of fungicides. 
These are frequently revised, and should be obtained when 
fungicides are to be prepared. 

OBSERVATIONS FOR PUPILS 

1. What methods of preventing plant diseases are employed in your 
neighborhood ? 

2. Do the more progressive farmers use the spraying machine or those 
less progressive ? 

3. Read such of these references as your teacher may request : — 

Spraying for Cucu.nber and Melon Diseases, Farmers' Bulletin 231. Fungicides 
and their Use in preventing Diseases of Fruits, Farmers' Bulletin 243. Insect and 
Fungous Enemies of the Grape east of the Rocky Mountains, Farmers' Bulletin 
284. Grape Diseases on the Pacific Coast, Farmers' Bulletin 30. 



CHAPTER XXV 

Fungous Diseases of Insects 

Did you ever notice on the window pane in autumn a 
dead, swollen fly sticking to the glass by its tongue and 
feet, with a circle of white, powdery dots about it resem- 
bling a halo, and with an abdomen so swollen that it 
seems to be made up of alternating black and white rings ? 
If you break the fly apart, you will probably find it brittle, 
and with a lens you can see whitish threads inside. 

This fly is the victim of a parasitic fungus somewhat 
similar to many of the fungi that cause disease and death 
in the higher plants. The white dots are the spores of 
the fungus thrown out from the fruiting threads that have 
developed in the body. By means of these spores other 
living flies may catch the disease and die. 

One who understands how dangerous flies are as carriers 
of the germs of typhoid fever and other diseases of man- 
kind will not regret that they themselves are thus destroyed 
by this parasitic fungus. Consequently it is easy to ac- 
knowledge that we have friends as well as foes in the great 
group of fungi. 

The halo-producing fly parasite is a typical example of 
the family of Insect-killing Fungi (Entomophthoreae). It 
belongs to the genus Empusa, so called because the Greeks 
in ancient times used the name Empusa when they fancied 
they saw " a weird specter of constantly changing shape." 

A parasitic fungus closely related to that which attacks 
the house fly often occurs in colonies of aphides or plant 

271 



272 



FARM FRIENDS AND FARM FOES 



lice. During moist weather, which is especially favorable 
to the growth of fungous diseases of insects, this aphid 
parasite often destroys billions of victims, checking destruc- 
tive outbreaks of crop pests. You can readily distinguish 
with a lens the plant lice that are killed by the fungus from 
those killed by insect parasites. 

A similar fungus is often very helpful in checking out- 
breaks of the chinch bug, and has been the subject of 
many investigations to determine whether it can be utilized 
as a remedy for this insect. Dead bugs covered with the 
whitish, moldlike growth of the fungus may generally 
be found wherever chinch bugs are abundant. While 
probably the artificial propagation and dissemination of 
the bugs hastens the spread of the malady, the success of 
the measure is largely dependent upon the damp weather 
favorable to the development of the disease. 

Fortunately these insect-killing fungi attack caterpillars 
of many kinds. A short search among cabbages will often 
show a cabbage worm killed by such a disease. The body 
of the caterpillar is filled with the fungous threads which 
convert it into a mummified condition, and finally produce 
upon the surface a crop of spores. Many other insects, es- 
pecially grasshoppers, are attacked by a similar disease. 

Caterpillar Fungi (Ascomycetes) 

Another group of these insect parasites attacks caterpil- 
lars of many kinds, and are often called the Caterpillar 
Fungi. They belong to the great group of Ascospore 
Fungi to which so many diseases of plants belong. They 
are readily distinguished by the strange, clublike projection 
in which the ascospores are developed. Two of these 
mushroom-like bodies coming from a fly are shown in the 
picture on the next page. White grubs are often killed 




FUNGOUS DISEASES OF INSECTS 273 

by a fungus belonging to this group, developing a curious 
growth that generally projects from the head. 

White Fly Fungi 

One of the most noted illustrations of the effect of para- 
sitic fungi upon injurious insects is found in the case of 
the White Fly or Aleyrodes, various species of which are 
destructive to orange and other trees in the Southern and 
Pacific coast states. Similar species are also 
destructive in greenhouses in the North. 
At least seven distinct forms of the fungi are 
known to attack these insects, and many 
successful experiments have been made in 
spreading the diseases artificially. The most Fly with 
effective way is by washing into water the 
spores that have developed on the insects killed by dis- 
ease, and spraying the water on the infested plants. The 
Florida Experiment Station has shown that this method is 
easy and effective. The spraying apparatus must have no 
copper in it, except the nozzle, as faint traces of copper are 
liable to kill the spores. Another method is simply to pin 
leaves covered with the dead insects upon the branches of 
trees that are infested by White Flies. The disease- 
producing fungi are most likely to spread during wet 
weather. 

Bacterial Diseases 

The diseases of insects due to Bacteria are perhaps 
more important than any others. When tent caterpillars, 
cutworms, army worms, or various other insects become ex- 
tremely abundant, they often die suddenly in great num- 
bers, seeming to be affected by a sort of cholera that causes 
death and rapid decay. This is a bacterial disease. 



274 FARM FRIENDS AND FARM FOES 

Not all bacterial diseases of insects, however, are 
helpful to man. The Foul Brood, which is so destructive 
to honey-bees, and the dreaded flaclierie of silkworms, afe 
both due to these microscopic germs. They cause great 
losses to the bee-raising and silk industries. 

OBSERVATIONS FOR PUPILS 

1. In autumn look for flies that show the ring of spores around them. 

2. Look for diseased aphides or plant lice, especially between cab- 
bage leaves and on clover plants. 

3. Keep watch for dead grasshoppers clinging to the tops of 
wire fences or herbaceous plants. 

4. If you live in a region where chinch bugs are found, hunt for 
dead, moldy specimens. 

5. If you live in a region where white flies are abundant, look 
for those killed by fungus, and try spreading the disease. 

6. When you find any of these diseased insects, place them in a 
glass, add a few drops of water, and cover tightly. Watch daily for the 
development of spores. Examine these under the microscope. 

7. Read this reference : — Nature Biographies, pages 89-95. 




Bacteria; highly magnified 



CHAPTER XXVI 

Bacteria and Plant Food 

It has been shown in an earlier chapter that the micro- 
scopic forms of life called microbes or bacteria often cause 
serious losses on account of the blights and rots that they 
induce in plants. Such bacteria are true parasites, develop- 
ing within the tissues of living plants and causing injury 
and death. It is well known that vast numbers of bacteria 
are similarly parasitic upon animal life, causing many of 
the most fatal diseases in man and the lower animals. 
Most of these forms of germ life must, of course, be 
reckoned among the farmer's foes. 

The Nitrifying Bacteria 

There are many other bacteria, however, that may well 
claim to be friendly to the farmer, for they serve an im- 
portant purpose in furnishing food to his crops. One 
group of these is present in vast numbers in fertile soils 
where they help to form the nitrates which are very im- 
portant in supplying food to plants. The plant or animal 
materials added to the soil for fertilizing purposes con- 
tain nitrogen in combination with various other elements. 
Consequently most of the nitrogen in the soil exists in the 
form of these organic compounds — that is, compounds 
made by organized or living things. In order that the 
nitrogen in these organic compounds may be utilized by 
growing plants, it must be recombined to form nitrates — 

275 



276 FARM FRIENDS AND FARM FOES 

that is, combinations of nitrogen, oxygen, and some element 
like lime or potash — which are readily absorbed through 
the roots of plants. 

There are certain sorts of bacteria the special function 
of which is to convert the organic nitrogen into nitrates. 
These are called the Nitrifying Bacteria. During this 
process the organic material is first converted into an am- 
monia form, then into a nitrite form, and finally into the 
nitrate form. In a general way this is a change from a 
condition in which the nitrogen is insoluble into a condition 
in which it is readily dissolved. 

During recent years the importance of this nitrifying 
process has received a great deal of attention. It is now 
recognized that good farming involves such treatment of 
the soil that these friendly germs may do as much work as 
possible, and that their abundance is an important test of 
soil fertility. 

The Nitrogen-gathering Bacteria 

In addition to the store of nitrogen in the soil which is 
unavailable until it is changed into the nitrate form by the 
nitrifying bacteria, there is an even greater store of it in 
the air. This supply is so great that it has been estimated 
that there are seventy-five million pounds of nitrogen rest- 
ing upon every acre of land. This nitrogen in the air, 
however, cannot be used directly by plants, so that it 
seems to have little value as a fertilizer. 

But here again the friendly germs come to the farmer's 
help. If you dig up a vigorous red clover plant and wash 
the soil carefully away from its roots, you will probably find 
upon the latter many small, roundish tubercles. If you treat 
a soy bean plant in the same way, you will find a condition 
like that pictured on the opposite page. And you may easily 



BACTERIA AND PLANT FOOD 



277 



find similar tubercles upon the roots of beans, peas, vetches, 
sweet clover, alfalfa, and various other members of the great 
family of legumes, or pod bearers. 

It took a long while for man to trace the connection 
between these tubercles upon the roots of the pod-bearing 
plants and the free nitrogen of the air. There is still much 
mystery about it, but we now know that the tubercles or 
nodules are composed chiefly of 
colonies of bacteria, and that these 
bacteria are able to convert the 
free nitrogen in the air between 
the soil particles into a form that 
is utilized by the plants. They 
may well be called the Nitrogen- 
gathering Bacteria, and are to be 
classed among the farmer's best 
friends. 

We have seen that some bac- 
teria may live as parasites upon 
living plants or animals : these are 
the Parasitic Bacteria. We have 
also seen that some bacteria — 
including the nitrifying forms — 
may live as saprophytes upon dead 

and decaying plants or animals: these are the Saprophytic 
Bacteria. We have now to determine the relation of the 
nitrogen-gathering bacteria to the leguminous plants. Evi- 
dently they are not parasites, for they help rather than in- 
jure the growth of the plant. Nor are they saprophytes, 
for they develop upon living rather than dead plants. They 
seem to form a sort of partnership with the plants. They 
need a home to grow in and some help to get their growth ; 
in return they gather nitrogen for the benefit of their hosts. 




Root of Soy Bean show- 
ing Tubercles 



278 FARM FRIENDS AND FARM FOES 

When we speak of two plants thus living together in mutual 
helpfulness, we use the word symbiosis : so we say that the 
nitrogen- gathering germs are Symbiotic Bacteina. 

These symbiotic bacteria are of great importance to prac- 
tical agriculture. In most good systems of crop rotation, 
clover or some other leguminous plant is grown every few 
years in order that the supply of available nitrogen in the 
soil may be increased. Clover is able to increase this supply 
because of the help given by the germs living in the nod- 
ules on the clover roots. One of the best ways to improve 
poor soil is to grow a leguminous crop and plow it under 
as green manure. The value of this process lies largely 
in the presence of the nitrogen-gathering bacteria. When 
an alfalfa field is well established, it may be left undisturbed 
except for harvesting the crops, for many years. Presum- 
ably it is able thus to yield its forage year after year be- 
cause the bacteria in the nodules on the roots are gathering 
free nitrogen from the air. 

A striking example of the effectiveness of these bacteria 
in gathering nitrogen has been recorded by the Illinois Ex- 
periment Station. Three sets of ten cowpea plants with 
tubercles on the roots were analyzed to determine the per- 
centage of nitrogen. Three other sets of ten cowpea plants 
without tubercles were also analyzed for comparison. " The 
infected plants contained nearly four times as much nitrogen 
as the plants not infected, and about three fourths of the 
total nitrogen in the infected plants was obtained from the 
air. The roots and tubercles of the infected plants con- 
tained six to seven times as much nitrogen as the roots of 
the plants not infected." 

It is an interesting fact that the bacteria found in nodules 
on the roots of red clover will not develop upon the roots 
of cowpeas or several other related plants. Similarly, the 



BACTERIA AND PLANT FOOD 



279 



bacteria from cowpeas will not develop upon red clover. 
Thus in a broad way we may say that each distinct legumi- 




Red Clover: Effect of Bacteria 

nous crop has a special form of symbiotic microbe and that, 
as a rule, these microbes are not interchangeable. 

Decay of Nodules 

Another important fact is that most of these bacteria 
are unable to live independently in the soil more than five 
or six years after the crop on which they develop has 
disappeared. Consequently we cannot expect to find in a 
given soil the various germs waiting to develop upon any 
leguminous crop that may be planted. Nor in most cases 
is it safe to assume that enough of these germs will adhere 



280 FARM FRIENDS AND FARM FOES 

to the seed and be planted with them to insure a good de- 
velopment of tubercles upon the roots. 

Consequently, the conditions that exist in a given case 
may be something like this : Here is a field in which no 
red clover has been grown in a dozen years. The soil is 
poor and sour. It produces very small crops and evi- 
dently needs to be improved. We wish to grow red clover 
to help its condition. Evidently we must get rid of the 
sourness by a liberal application of lime or some other 
alkaline fertilizer. Then we must introduce the clover 
tubercle germs into the soil and sow the seed. Such intro- 
duction of germs is often spoken of as inoculation — that 
is, we inoculate the soil with the desired microbes in the 
expectation that when introduced they will thrive and 
multiply upon the clover roots. One of the simplest ways 
of inoculating is to bring a quantity of soil from a field in 
which clover has been growing successfully. Being sure 
that the plants grown in the soil have shown plenty of 
nodules, spread it broadcast and harrow it in. We may 
thus get a very general dispersal of the germs where they 
will come in contact with the developing clover roots. 

Another way to inoculate the soil is to shake up in a 
bottle of water a small quantity of soil from a thriving 
clover field. Let it stand until the soil particles settle, and 
pour the clear liquid over the clover seed or upon the soil 
where the seed is planted. This method is especially use- 
ful in pot experiments. 

Fortunately, these nitrogen-gathering bacteria can be 
induced to develop in vast numbers in what are called 
nutrient solutions. The scientists of the United States 
Department of Agriculture have been at work for many 
years upon the methods of growing bacteria in such solu- 
tions. They have succeeded so well that the Department 



BACTERIA AND PLANT FOOD 281 

now offers to the public small culture tubes of the microbes 
of each of the important leguminous crops, with precise 
directions for their use. This enables any one to inoculate 
his soil for any crop desired. 

Experience has shown that with some crops at least it is 
worth while at first to grow the same crop for two suc- 
cessive seasons in order to secure a thorough inoculation of 
the soil. After that, if the crop is grown in rotation every 
four or five years, the microbes are likely to continue 
present in such numbers that further inoculation is un- 
necessary. 

The germs that grow upon cowpeas seem very generally 
present in the soil of the Southern states. Consequently 
it is seldom necessary to inoculate for this crop. 

The germs that grow upon sweet clover or melilot seem 
to be able to develop with equal vigor upon alfalfa. Con- 
sequently, it is often practicable to inoculate alfalfa fields 
with soil in which sweet clover has been growing. 

OBSERVATIONS FOR PUPILS 

1. Make a list of the leguminous plants in your locality upon which 
you find root tubercles. 

2. Compare the abundance of the tubercles with the vigor of the 
plant. 

3. Grow red clover in sand or other soil deficient in nitrogen, being 
sure it is from a field where red clover has not grown. Apply the 
germs obtained as suggested on page 280, to part of the pots, but not to 
all. See which set grows best, making sketches every two weeks. 

4. Read such of these references as your teacher directs : — 

Leguminous Crops for Green Manuring, Farmers' Bulletin 278. Progress in 
Legume Inoculation, Farmers' Bulletin 315. The Renovation of Worn-out Soils, 
Farmers' Bulletin 245. Alfalfa, Farmers' Bulletin 339. Clover Farming on the 
Sandy Jack-pine Lands of the North, Farmers' Bulletin 323. Canadian Field 
Peas, Farmers' Bulletin 224. Cowpeas, Farmers' Bulletin 318. The Liming of 
Soils, Farmers' Bulletin 77. 



PART IV 

FRIENDS AND FOES AMONG THE 

BIRDS 







sJiRvcr 



A Page from a Bird Booklet 



The Booklet on Birds 

Birds are more difficult to draw than plants or insects. Consequently 
this booklet is likely to have fewer pages of drawings of the birds themselves, 
though these may readily be replaced by drawings of fruits, seeds, and insects 
which are eaten by birds, as well as by mounted pictures cut from magazines. 

Abundant opportunities for written or printed pages may be found in the 
suggestions at the ends of the chapters on birds. Delightful poems con- 
cerning birds are readily found and may be copied for the booklet. 



CHAPTER XXVII 
The Relations of Birds to Fruit Orchards 

In a large part of North America the apple is the lead- 
ing orchard fruit. The pear and the peach are much less 
generally grown, although each is important in certain 
localities. The same is true of cherries, plums, and quinces, 
though in the aggregate each of these fruits is of great 
value. 

These orchard trees are subject to attack by a great variety 
of insect enemies. Root, trunk, branch, twig, leaf, and 
fruit — each part has special enemies that too often blight 
the crop. Fortunately, however, most of these enemies are 
largely held in check by various birds that frequent the 
orchards and help to keep a balance that is favorable to 
fruit production. Where birds are scarce the task of fruit- 
raising is greatly increased. 

Trunk, Roots, and Branches 

The trunk and the larger roots and branches of most 
fruit trees are subject to attack by a great variety of burrow- 
ing insects. In general, the eggs are laid on or in the bark 
by a winged beetle or moth. These eggs hatch into larvae 
that burrow in bark, sapwood, or heartwood, remaining at 
work until full grown as larvae. They then change to pupae, 
generally in or near the outer bark, and emerge later as 
adult beetles or moths. 

Common examples of such destructive insects are found 
in the round-headed apple-tree borer, the flat-headed borer, 

285 



286 FARM FRIENDS AND FARM FOES 

the peach-tree borer, the fruit-bark beetle, and the sinuate 
pear borer. 

Set over against these enemies of trunk and branch, we 
find the woodpeckers, nuthatches, creepers, and chickadees. 
These birds are constantly searching the bark for the larvae 
and pupae concealed within, and they are wonderfully adapted 
both to discover the position of the pests and to dig them 
out. The long, barbed tongue of the woodpecker can be 
thrust into the hole made by a borer and draw the larva 
quickly forth. The larger and more deeply embedded 
larvae are especially sought by the woodpeckers, while the 
smaller insects on or near the surface are eaten by the 
nuthatches, creepers, and chickadees. 

The twigs or smaller branches of fruit trees are attacked 
by a great variety of insect enemies. The sap is sucked 
through the bark by hosts of scale insects or bark lice, and 
aphides or plant lice, as well as by tree hoppers and related 
pests. Many of the birds already mentioned feed freely 
upon these various insects, the nuthatches, creepers, and 
chickadees being especially useful in this respect. These 
are not alone, however, in the good work. They are 
assisted by the orioles, sparrows, vireos, warblers, gros- 
beaks, wrens, gnat catchers, bluebirds, and other feathered 
friends. In the case of the scale insects alone, fifty-seven 
kinds of birds have been listed as feeding on them. 

Buds and Leaves 

When we consider the relations of birds to the enemies 
of the buds and leaves of orchard trees, we find so close a 
connection that we are forced to conclude that the life of 
the trees depends upon the birds. Tree leaves are beset by 
a bewildering host of insect enemies. Aphides, scale in- 



RELATIONS OF BIRDS TO ORCHARDS 



287 



sects, leaf hoppers, and many other true bugs suck out the 
sap ; leaf miners of many sorts mine the leaves ; while 
beetles, grasshoppers, crickets, and numberless caterpillars 
devour the blades. 

Set over against these myriads of leaf-feeding insects, 
we find the great majority of our familiar birds. Watch 
the birds in an orchard on a summer day and you will be 
convinced of their great value 
as insect destroyers. If you 
are keen-eyed and patient, 
you will see the warblers and 
other smaller birds searching 
leaf after leaf for aphides and 
tiny caterpillars, while vireos, 
bluebirds, robins, thrushes, 
sparrows, cedar birds, cuckoos, 
catbirds, blackbirds, and others 
are devouring the larger en- 
emies. If you watch these 
birds at their nests, you will 
see that the young are fed 
with vast numbers of such 
insect foes. Even in winter 
the eggs and pupae are con- 
tinually eaten by birds. 

The enemies of the fruits of orchard trees are less 
numerous than those of the leaves, but still their name is 
legion. Scale insects, beetles, bugs, caterpillars, maggots, 
midges, and other pests all attack one kind of fruit or 
another, often destroying the bulk of the crop. The birds 
that attack these enemies are nearly as numerous as those 
that attack leaf-feeding insects, and the good they do is 
incalculable. 




Tent-caterpillar Nest at- 
tacked by Birds 



288 FARM FRIENDS AND FARM FOES 

What is true of the relations between insects and birds 
in orchards of deciduous fruits is equally true in orchards 
of citrous fruits. Wherever oranges, lemons, and related 
trees are grown for profit, hosts of insect enemies attack the 
trees. These insects are preyed upon by birds which help 
greatly in checking the injuries of the pests. 

Aerial Insects 

Nearly all the insects that affect orchards exist part of 
their lives in a winged condition in which they fly through 
the air from branch to branch or from tree to tree. At 
such times they are in danger of being snapped up by 
flycatchers, vireos, swallows, and other birds. Most of 
these keep watch over comparatively limited spaces near 
the trees, but the whole realm of the air is patrolled 
by the swallows. Over the water or above the land the 
flying insect is in danger of being suddenly captured in the 
swallow's beak. The food of swallows consists chiefly of 
insects thus caught upon the wing ; beetles, flies, ants, and 
small moths are all taken in great numbers. Consequently, 
these birds are as useful as they are beautiful, and should 
be encouraged by every one. 

At night, also, the war against flying insects is kept up 
by the whippoorwills and nighthawks. These interesting 
birds patrol the air in dusk and darkness, catching flying 
insects of many kinds in their capacious jaws. 

Other Enemies 

There are other enemies of orchard trees besides the in- 
sects. The trunks are frequently girdled by meadow mice 
and rabbits that gnaw the bark. This generally happens 
in winter, when the mice work beneath the surface of the 






RELATIONS OF BIRDS TO ORCHARDS 289 

snow. Fortunately, however, hawks, owls, and other large 
birds feed freely upon these pests and commonly keep 
their numbers so reduced that little damage is done. But 
in regions where the hawks and owls are ruthlessly perse- 
cuted, the mice and other rodents become destructive, and 
often cause the loss of valuable trees. 

It would perhaps be too much to expect that birds 
should do no harm in orchards to offset the immense good 
they do. In certain ways they doubtless cause damage, 
but this is on the whole vastly less than the benefit they 
confer. Some birds eat fruit, especially cherries, to a 
serious extent. It is indeed probably true that in fruit- 
growing regions there are often more robins than are 
beneficial to horticulture. 

Birds also cause the spread of scale insects and probably 
of fungous diseases, although little real injury is done in 
these ways. At least one bird — the true sapsucker — 
sometimes injures the trees by boring holes in the bark 
and taking the sap, though this should not lead to the 
killing of the beneficial woodpeckers, which the sapsucker 
resembles. 

The chief damage done to fruit by birds generally 
results from the extraordinary abundance of one kind of 
bird. Thus, in the eastern region of the United States the 
robin is often troublesome because it occurs in great num- 
bers and attacks cherries and small fruits. On the Pacific 
coast it is sometimes very destructive in olive orchards. 
In the latter region birds are more injurious to fruit than 
in the East, partly because of the scarcity of wild fruits. 
The house-finch or linnet, the Brewer blackbird, the black- 
headed grosbeak, and the California jay often become 
serious pests, although each of these doubtless does con- 
siderable good in other ways. 



290 FARM FRIENDS AND FARM FOES 

OBSERVATIONS FOR PUPILS 
Birds in Apple Orchards 



i . Make a list of the birds you have seen searching the bark of the 
trunk and larger branches of apple trees. 

2. What birds occur on apple trees in winter? 

3. What birds have the habit of snapping up insects in the air? 

4. Make a list of all the different birds that you can find in apple 
orchards. 

B 

1. Write a little story with this title : The Birds in Our Orchard. 
Simply tell what you have seen. 

2. Read as many of these references as you have access to : — 

Birds in their Relation to Man, pages 1-8, 68-8o, 304-315. Useful Birds and 
their Protection, pages 149-154. How Birds Aftect the Orchard, Yearbook Reprint 
197. Does it Pay the Farmer to Protect the Birds? Yearbook Reprint 443. The 
Relations between Birds and Insects, Yearbook Reprint 486. 



CHAPTER XXVIII 
The Relations of Birds to Meadows and Pastures 

While the insects that affect the grasses of meadow 
and pasture lands are by no means so numerous as in the 
case of the orchards, there are enough to prove seriously 
destructive at times. If this is true with the constant 
check the birds keep upon them, there is little doubt that 
they would do vastly greater damage were there no birds. 

The various forms of locusts or grasshoppers with short 
antennae are among the most abundant of meadow and 
pasture pests. They are nearly always present in sufficient 
numbers to do some damage, and often become so abundant 
as to destroy the growing crop. The meadow grasshoppers 
with long antennae, are often abundant enough to do some 
injury. The much smaller leaf hoppers are also nearly al- 
ways present and do much more damage than is generally 
supposed. Many sorts of cutworms, including the notorious 
army worm, are always feeding on the blades of grass near 
the ground, and other kinds of caterpillars 
are continually at work. 

In addition to these enemies of the stems 

and blades, the roots of grasses are attacked 

by many pests. The voracious white grubs 

— the larvae of the familiar May beetles; the 

slender yellow wireworms — the larvae of the 

. May Beetle 

common click beetles; the curious meadow 

maggots — the larvae of the long-legged crane flies, — -these 

and many other pests feed upon the roots of grasses. 

291 





292 FARM FRIENDS AND FARM FOES 

The clovers and other forage crops often grown in mead- 
ows have their special insect enemies that furnish food for 
many birds. 

The variety of bird life that is found in grasslands is 
also much smaller than in the case of orchards. Compar- 
atively few species have adapted themselves to live upon 

the ground in grasses, but these few 
are of immense benefit as destroyers 
of insect pests. 

The most notable meadow and 
pasture birds are these : the meadow 
lark, the crow, the various black- 

Click Beetles birds ' the bobolink, the cowbirds, 

the ground sparrows, and the robin. 

While these do not all live exclusively on the ground in 

grasslands, they find there an important part of their yearly 

food supply. 

The Meadow Lark is a typical example of these birds. It 
is an abundant and widely distributed species, living habit- 
ually in grasslands and finding there practically all its food. 
Originally a native of the great prairie regions, it has grad- 
ually spread as forests have been replaced by fields and 
meadows until it is now found over practically the whole 
of the United States. 

The food of the Meadow Lark has been carefully studied 
by many competent investigators. In Illinois Professor 
Forbes found that at least three quarters of the food during 
the spring and summer consisted of insects. Cutworms, 
army worms, and other caterpillars formed more than a 
quarter of the food supply, while various beetles formed a 
fifth and grasshoppers more than an eighth. The beetles 
eaten included June beetles, blister beetles, curculios, 
click beetles, and plant beetles. Twenty chinch bugs 




RELATIONS OF BIRDS TO MEADOWS 293 

had been eaten by one bird, and others had devoured 
crane flies. 

Studies in other places show similar results and bring 
out the fact that in autumn when insects become more 
scarce the Meadow Lark feeds freely upon the seeds of 
weedy plants. It consequently is of great value wherever 
it is found, and should be given the most careful protection. 

The Bobolink is one of the most delightful of meadow 
birds. It is also one of the most useful, for it feeds freely 
on grasshoppers, caterpillars, and 
other insect pests as well as on the 
seeds of weedy plants. In the 
North it is eminently beneficial, 
though on its way southward it 
often becomes a pest in rice fields. 

While it cannot fairly be claimed MEADOW Grassh0 pper 
that the Crow and the various 

Blackbirds are entirely beneficial, there is no doubt that 
they do much good to offset some harm. So far as their 
actions concern meadows and pastures, these birds are of 
benefit, for they devour vast numbers of grasshoppers, 
cutworms, army worms, white grubs, June beetles, and 
other pests. The harm they do is chiefly in grain fields, 
either at the time of planting or that of harvesting. 

There are several kinds of Sparrows that live more or 
less on the ground in pastures and meadows. The more 
important are these : the Field Sparrow, Song Sparrow, 
Vesper Sparrow, Savanna Sparrow, and the Dickcissel. 
All of these birds feed freely upon grass insects, destroying 
vast numbers of crickets, grasshoppers, cutworms, and other 
caterpillars, as well as the seeds of weedy plants. The 
young are also fed with similar insects, so that these birds 
are eminently beneficial. 



294 



FARM FRIENDS AND FARM FOES 



The presence of flocks of Robins searching grasslands 
for food is one of the characteristic sights of early spring. 
At no other season, perhaps, do these birds search so 
persistently upon the ground. A large proportion of the 
grasshoppers, cutworms, army worms, and "other grass 
insects that have succeeded in living through the winter 

are then eaten by the 
Robins. This early 
spring destruction of 
such pests is of great 
value in checking their 
increase, and the birds 
atone for many sins in 
the cherry trees by 
their actions at this 
season. 

No consideration of 
the relations of birds 
to insects of grass- 
lands would be ade- 
quate that did not 
take account of the 
flycatchers, swallows, 
swifts, whippoorwills, and nighthawks, a large part of 
whose food consists of grasshoppers, leaf hoppers, beetles, 
moths, and other pests of grasslands. 

As their name indicates, the meadow mice are often very 
destructive in pastures and meadows. They destroy much 
grass by feeding upon crowns or roots, and their runways 
in spring often show how busy they have been beneath 
the snow in winter. The hawks and owls are the most 
important natural checks upon these pests. The experi- 
ences of many regions show that where these birds are 




Screech Owl 



RELATIONS OF BIRDS TO MEADOWS 295 

relentlessly persecuted, the meadow mice are likely soon 
to multiply to an alarming extent, sometimes destroying the 
crops in whole fields. 

OBSERVATIONS FOR PUPILS 
Birds in Meadows and Pastures 

1. Make a list of the most important grass-feeding insects in your 
locality. 

2. Make a list of the birds you have seen upon the ground in pas- 
tures or meadows, or both. 

3. Make a list of the birds that build their nests on the ground in 
pastures and meadows. 

4. Read as many of the following references as are accessible : — 

Farmers' Bulletin 54, pages 15-28. The Bird Book, pages 248-253. Birds in 
their Relations to Man, pages 137-144, 158-171. Useful Birds and their Protection, 
pages 76-80, 310-333. 



CHAPTER XXIX 
The Relations of Birds to Gardens and Fields 

The conditions in regard to the crops and insects of 
gardens and cultivated fields vary in different regions. 
Consequently, it seems best to indicate the relations of 
birds to them by considering a few of the more widely 
distributed species that live chiefly in such situations. 

Sparrows 

The little Chipping Sparrow is one of the most abun- 
dant of the smaller birds found in gardens and fields near 
houses. In the North it arrives early in spring and remains 
till late in autumn. Its food consists of insects and the 
seeds of grasses and weeds. Nearly half of the food often 
consists of the seeds of such noxious plants^ as pigeon 
grass and crab grass. Cutworms, cankerworms, bugs, 
moths, ants, beetles, and grasshoppers are among the 
insects eaten by both young and adults. In consequence 
of such feeding habits, this familiar little bird is very use- 
ful and should be encouraged in every way possible. 

On account of its attractive voice the Song Sparrow is 
perhaps an even greater favorite than the Chipping Spar- 
row. It is found everywhere in fields and gardens, keep- 
ing close to the ground where insects and weed seeds are 
abundant. It remains through the winter as far north as 
Massachusetts. 

The other native ground-loving sparrows — such as the 
Field Sparrow, the Savanna Sparrow, the Vesper Sparrow, 

296 



RELATIONS OF BIRDS TO GARDENS 297 

and the Junco — have similar feeding habits. They are 
especially useful as destroyers of the seeds of weeds. In 
this respect, however, they are probably surpassed by the 
related sparrows that do not live so much upon the ground. 
These include the Tree Sparrow, the Goldfinch, the White- 
crowned Sparrow, the White-throated Sparrow, and the 
Snowflake. These are preeminently seed eaters, and they 
undoubtedly destroy thousands of tons of weed seeds every 
year. 

The bird commonly known as the English Sparrow 
was brought into America from Europe in 1850 and again 
three years later. These birds were imported because it 
was thought that they would assist in the suppression of 
the cankerworm, an insect very destructive to the leaves 
of shade trees. After their introduction they thrived and 
spread rapidly, being carried by man from city to city so 
that before many years they were very generally distrib- 
uted. 

English sparrows are by preference city birds; they utilize 
all sorts of crevices about buildings for nesting and roost- 
ing purposes, and live upon a great variety of food. From 
towns they gradually disperse through the surrounding 
country, congregating about farm buildings. They breed 
rapidly, and have few enemies. When well fed, they can 
stand very cold weather without injury. 

As a destroyer of noxious insects, this sparrow has been 
generally, though not always, a failure. There are also 
many misdemeanors charged to him. It is known that he 
habitually destroys the buds and blossoms of trees, and at- 
tacks ripening fruit of many kinds, as well as peas on the 
vines and seeds in the soil. Grains in the field are also 
devoured by the sparrows ; houses are made filthy by their 
presence ; and native birds are driven away by them. 



298 FARM FRIENDS AND FARM FOES 

With these and other charges the sparrows stand indicted ; 
and they have comparatively little good to counterbalance 
the evil. Consequently, it would seem that they should 
not be encouraged near farm buildings. 

Bluebirds, Robins, and Catbirds 

Next to the sparrow, the Bluebird is one of the most 
abundant species found in gardens and cultivated fields. 
Fortunately, this universal favorite is as useful as it is beau- 
tiful. Its food has been most carefully studied by Profes- 
sor S. A. Forbes, who writes : " One hundred bluebirds at 
thirty insects each a day would eat in eight months about 
730,000 insects. If this number of birds were destroyed, 
the result would be the preservation on the area supervised 
by them of about 70,000 moths and caterpillars (many of 
them cutworms), 12,000 leaf hoppers, 10,000 curculios, and 
65,000 crickets, locusts, and grasshoppers. How this 
frightful horde of marauders would busy itself if left un- 
molested no one can doubt. It would eat grass and clover 
and corn and cabbage, inflicting an immense injury itself 
and leaving a progeny that would multiply that injury 
indefinitely." 

The Robin is very useful in destroying insects that live 
on or in the ground. It feeds freely upon such pests as 
cutworms, white grubs, and grasshoppers. It is especially 
busy in meadows when it first arrives in early spring. 

The food of the Robin as determined by the investiga- 
tions of the United States Department of Agriculture has 
been summarized as follows : " An examination of 300 
stomachs shows that over 42 per cent of its food is animal 
matter, principally insects, while the remainder is made 
up largely of small fruits or berries. Over 19 per cent 



RELATIONS OF BIRDS TO GARDENS 299 

consists of beetles, about one third of which are useful 
ground beetles, taken mostly in spring and fall when other 
insects are scarce. Grasshoppers make up about one 
tenth of the whole food, but in August comprise over 30 
per cent. Caterpillars form about 6 per cent, while the 
rest of the animal food, about 7 per cent, is made up of 
various insects, with a few spiders, snails, and angle 
worms.. All the grasshoppers, caterpillars, and bugs, with 
a large part of the beetles, are injurious, and it is safe to 
say that noxious insects comprise more than one third of 
the robin's food. Vegetable food forms nearly 58 per cent 
of the stomach contents, over 47 being wild fruits, and only 
a little more than 4 per cent being possibly cultivated va- 
rieties. Cultivated fruit amounting to about 25 per cent 
was found in the stomachs in June and July, but only a 
trifle in August. Wild fruit, on the contrary, is eaten in 
every month, and constitutes a staple food during half the 
year. No less than 41 species were identified in the 
stomachs ; of these, the most important were four species 
of dogwood, three of wild cherries, three of wild grapes, 
four of greenbrier, two of holly, two of elder ; and cran- 
berries, huckleberries, blueberries, barberries, service ber- 
ries, hackberries, and persimmons, with four species of 
sumac, and various seeds not strictly fruit." 

There is no doubt that the Robin is a very useful bird, 
when we consider its life through the year. But it is also 
true that at times, especially in fruit-growing regions, it is 
decidedly injurious. 

No country boy needs to be introduced to the Catbird. 
It is familiar to every one who has wandered along a 
roadside or by the margin of woods. It is a useful bird, 
although it sometimes helps itself too freely to the fruits 
of the orchard and garden. "Ants, beetles, caterpillars, 



3°° 



FARM FRIENDS AND FARM FOES 



and grasshoppers constitute three fourths of the animal 
food," writes Professor Beal, " the remainder being made 
up of bugs, miscellaneous insects, and spiders. One 
third of the vegetable food consists of cultivated fruits 
or those which may be cultivated, such as strawberries, 
raspberries, and blackberries ; but while we debit the bird 
with the whole of this, it is probable — and in the eastern 
and well-wooded part of the country almost certain — that 
a large part was obtained from wild vines. The rest of 
the vegetable matter is mostly wild fruit, such as cherries, 
greenbrier, spice berries, black alder, sumac, and poison 
ivy." About half of the food of the Catbird is of animal 
and half of vegetable nature. Planting wild fruits in out- 
of-the-way corners is recommended to keep these birds 
away from the fruit garden. 

Blackbirds and Crows 

Two kinds of Blackbirds are generally to be found in the 
Northern states. The larger of these is the Crow Black- 
bird, of which there are two forms — the Bronzed Grackle and 
the Purple Grackle, large and handsome birds, familiar to 
country boys throughout their range. Their food consists 
of insects, grains, and other vegetable matter, insects 
forming about one third of the total. These birds are 
frequently destructive to ripening wheat or other grain 
crops, and no doubt often do as much harm as good. But 
in general they should not be molested except when 
causing damage. 

The Redwinged Blackbird is smaller than the Grackles, 
although in regions favorable for its breeding it is likely to 
be much more abundant. It builds its nest in low bushes 
on the borders of swamps ; and in the West often appears 



RELATIONS OF BIRDS TO GARDENS 301 

in enormous flocks in grain fields, doing much damage. 
But its injuries are partly atoned for by the fact that it eats 
large numbers of injurious insects, many of them being 
grain-destroying pests. 

In the Pacific coast region the Brewer Blackbird is 
abundant. Its friends have to confess that it is fond of 
cherries, but they also claim that it is a great destroyer 
of insects. When Professor F. E. L. Beal was studying 
these birds as they were eating fruit in a California cherry 
orchard, a neighboring fruit grower began plowing. " Al- 
most immediately every blackbird in the vicinity was upon 
the newly opened ground, and many followed within a few 
feet of the plowman's heels in their eagerness to get every 
grub or other insect turned out by the plow." 

There is a great difference of opinion about the economic 
relations of the common crow — a bird that is abundant 
over most of the United States. Many people accuse it, 
and with justice, of pulling up sprouting corn, robbing 
birds' nests, and carrying off young chickens as well as of 
eating small wild animals — such as toads, frogs, and 
snakes — which are beneficial to man. To counterbalance 
these sins, however, it is certain that the crow destroys 
large numbers of noxious insects. It also feeds freely 
upon various wild berries and fruits, including the sumac, 
dogwood, sour gum, and poison ivy. 

The chief injury to corn is done by the birds pulling up 
the young plants or feeding upon the swollen kernels after 
they become softened by the moisture of the soil. 

Flycatchers, Swifts, and Swallows 

A distinct phase of the war against insect pests is car- 
ried on by Flycatchers such as the Phcebe and the King- 



302 FARM FRIENDS AND FARM FOES 

bird. These perch upon fences, trees, tall weeds, or posts 
wherever they can watch the surrounding air space. 
When a fly, moth, beetle or other insect comes near, the 
bird sallies forth and snaps it in its beak. In this way 
they get nearly all their food. 

In the case of the Phoebe more than nine tenths of the 
food consists of insects and spiders, chiefly those caught 
in the air. In the case of the Kingbird the proportion is 
almost as great. To a less extent the Bluebird and the 
Cedar Bird have similar fly-catching habits. 

The greater spaces of the air over gardens and culti- 
vated fields are patrolled during the day by the Swifts and 
Swallows and during the night by the Whippoorwills and 
Nighthawks. All of these spend hours upon the wing, 
continually catching the myriads of winged insects that fly 
from place to place. The service thus rendered is of in- 
calculable value, and every one should strive to protect 
these feathered friends from enemies of every sort. 

It is commonly believed that the Hawks and Owls are 
enemies of the farmer, to be destroyed whenever possible. 
But the careful studies and observations of many com- 
petent observers show that a majority of these birds are 
friends whose presence we could scarcely afford to lose. 
They destroy great numbers of mice and insects, and in 
Europe are recognized as beneficial birds. 

The Marsh Hawk is one of the most useful birds of 
prey, and deserves man's protection. " Its food," writes 
Dr. A. K. Fisher, "consists largely of small rodents, such 
as meadow mice, half-grown squirrels, rabbits, and ground 
squirrels." The stomach of a New Hampshire specimen 
that I examined was full of grasshoppers. 

The Sparrow Hawk is a small species that feeds almost 
wholly upon insects, chiefly grasshoppers, when these can 



RELATIONS OF BIRDS TO GARDENS 303 

be obtained. In the sparse pine woods of southern Florida 
I have found the Sparrow Hawk one of the commonest 
winter birds. One of its favorite methods of obtaining 
food there is to perch in trees on the outskirts of the forest 
fires that frequently occur, and catch the grasshoppers, 
lizards, and other animals driven from cover by the flames. 

OBSERVATIONS FOR PUPILS 

Birds in Gardens and Fields 

A 

1. Write a short account of birds that you have found in the yard 
and garden about your house. Tell what kinds you have seen and 
what you have observed them eating. 

2. If the English Sparrow is found near your home, write a special 
essay about it. Tell whether it drives away other birds, what it feeds 
upon, where the nest is made, and how many broods there are each 
season. 

B 

1. Write a short essay with this title : My Favorite Bird. 

2. Illustrate your booklet with such drawings as you can make, 
and if you have bird pictures in magazines or papers that can be cut 
out, paste them in also. 

3. Look up the discussions of the field and garden birds you are 
most interested in as found in these references : — 

The English Sparrow, Farmers' Bulletin 383. The Meadow Lark and Balti- 
more Oriole, Yearbook Reprint 37, Part 2. The Food of Nestling Birds, Year- 
book Reprint 194. Birds in their Relations to Man, pages 156-173. 



PART V 

FRIENDS AND FOES AMONG THE 
MAMMALS 




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PRAIRIC DOO BURR07: 5ECTI0MAL Vltvy 

FROM THE BIOLOGICAL SURVEY 



The Booklet on Mammals 

It will probably be more difficult to get abundant material for this booklet 
than any other. It is consequently less essential that one should be made. 

The booklet may well be made up largely of the observations and experi- 
ences of each pupil concerning the mammals most abundant in the locality 
of the school. It may readily be enriched by the use of pictures cut from 
magazines and mounted upon sheets of drawing paper. 



CHAPTER XXX 

The Squirrels 

The four-footed animals help to form a group called the 
Mammals. Some of the wild mammals are helpful on the 
farm, but many more are hurtful. The great majority of 
the latter belong to the order of Rodents or Gnawing Ani- 
mals, of which squirrels, rats, mice, and rabbits are familiar 
examples. One of the chief characteristics of this group 
is the curious front teeth which are chisel-like and continue 
to grow as long as the owner lives ; they are called incisors. 
The rodents have to be continually gnawing in order to 
keep these incisor teeth short enough for comfort. 

Nearly all the rodents feed upon plant materials, and 
many of them are especially fond of various farm and 
garden crops. Some, however, as the common rat, are 
practically omnivorous. 

The interesting family of Squirrels (Sciuridae) includes 
the True Squirrels, the Marmots, and the Flying Squirrels. 
The True Squirrels are divided into three groups : the 
Tree Squirrels, of which the Gray Squirrel and Red 
Squirrel are familiar examples ; the Rock Squirrels, of 
which the Chipmunk is an example, and the Ground Squirrels 
or Spermophiles. The Marmots include the Woodchuck 
and Prairie Dog. 

Ground Squirrels or Spermophiles 

The Ground Squirrels or Spermophiles are now classified 
in the genus Citellus. They are often called Gophers, 

307 



308 FARM FRIENDS AND FARM FOES 



although this much -abused word is more properly restricted 
to the family of rodents commonly called Pocket Gophers 
These differ greatly in structure and appearance from the 
ground squirrels. 

The Spermophiles bear a rather striking general resem- 
blance in habits to the Chipmunks. They are ground-loving, 
grain-eating squirrels, varying into more than seventy 
species or subspecies in the Western regions where they 
occur. They are known to cause an annual loss of many 
millions of dollars, chiefly through their injuries to grain 
and forage crops. They have recently been suspected of 
carrying germs of the deadly disease known as bubonic 
plague, so that they may become a menace to human life. 

The Leopard Spermophile, also known as the Thirteen- 
lined or the Striped Spermophile, is one of the most 
abundant and widely distributed species of ground squir- 
rels. It occurs from Michigan and Minnesota west to 
the Rocky Mountains and south to Texas. It lives in 
burrows about two inches in diameter and not more than 
two feet below the soil surface. The length of these 
burrows varies greatly ; some are mere pockets for tem- 
porary shelter, while others extend horizontally for many 
feet. During summer the Spermophiles come forth from 
their burrows in search of seeds of weeds, grains, grasses, 
the succulent root stems and leaves of clover, alfalfa, and 
other forage crops, as well as grasshoppers and other in- 
sects. All these materials serve for food. While some 
benefit to man is derived from the grasshoppers destroyed, 
it is more than counterbalanced by the injury done to 
grain, forage, and other crops. 

Early in autumn the Leopard Ground Squirrels store 
up seeds and grain in their burrows. When winter comes, 
they fall into a hibernating sleep that lasts about five 



5. 



THE SQUIRRELS 309 

months, after which they awake and feed upon the stored 
seeds and such other food as they can find outside. Dur- 
ing this spring season they dig up newly planted corn and 
other seeds. The young are generally born in April, 
there being six to ten in each litter. 

In Wyoming, the Dakotas, and neighboring states the 
Gray Ground Squirrel or Franklin's Spermophile is the 
most abundant species. It bears a striking resemblance to 
the tree-loving Gray Squirrelof the Eastern states. It feeds 
on grain and forage crops as well as upon field mice and 
grasshoppers and other insects. It has also a fondness 
for young chickens that makes it a troublesome neighbor 
where poultry is raised. 

In arid or semiarid regions where irrigation is practiced, 
various species of ground squirrels do much damage to the 
irrigation ditches by burrowing into them and deflecting 
the water. 

Fortunately for man, these ground squirrels form the nat- 
ural food of many predaceous mammals and birds. Such 
animals as coyotes, badgers, foxes, and skunks feed freely 
upon them. Hawks, owls, and eagles are always after 
them. The general destruction of these natural enemies 
has been an important reason for the increase in the num- 
bers of ground squirrels. 

The most practical means of destroying these pests di- 
rectly is the use of poisoned food. Grain or green alfalfa is 
saturated with strychnine and placed in the burrows. Care 
is always needed, however, to avoid accidents to people, 
birds, and domestic animals. Precise instructions as to 
the best methods may be obtained upon application to the 
Biological Survey, United States Department of Agri- 
culture. 



310 FARM FRIENDS AND FARM FOES 

Marmots 

The Marmots are represented in the United States by two 
animals of peculiar interest — the Prairie Dog and the 
Woodchuck. These are grouped in the squirrel family on 
account of their general structure, although different in 
appearance and habits from the typical squirrels. 

The Prairie Dogs inhabit a great area west of the Mis- 
sissippi River from Texas to Canada. They are especially 
abundant in prairie regions, where they often live in colo- 
nies of many hundred families. Each family occupies a 
burrow having a mound of earth at the entrance to keep 
out water. The details of a typical burrow are shown in 
the diagram on page 306. 

The Prairie Dogs feed upon a variety of grains and 
grasses. They are troublesome because of the food they 
consume, the hillocks of soil they make, and the burrows 
they dig. They are preyed upon by many natural enemies : 
among these coyotes, wolves, foxes, owls, ferrets, and rattle- 
snakes are the most important. In wild regions these 
foes serve to keep their numbers reduced, but as land is 
brought into cultivation the destruction of natural ene- 
mies leads to the increase of Prairie Dogs. They are 
readily destroyed, however, by placing poisoned grain at 
the mouth of their burrows or by the use of carbon 
bisulphide. 

Nearly every farmer's boy in the eastern region of the 
United States is familiar with the Woodchuck or "Ground- 
hog." This is one of the largest of the rodents, and its 
burrows are to be found on many farms in the hill regions 
of the Northeastern states. It feeds ravenously upon clovers 
and forage crops as well as upon beans, peas, cucumbers, 
and many other field and garden vegetables. In autumn 



THE SQUIRRELS 311 

it develops a thick layer of fat beneath the skin and retires 
to the burrow to hibernate. 

Woodchucks are commonly trapped or shot, but the easi- 
est way to kill them is by means of carbon bisulphide. A 
little of this volatile liquid is poured upon a tuft of dry moss 
or other absorbent material which is then rolled into the 
burrow. The openings are now closed by sods or soil, and 
the liquid will vaporize into a deadly gas heavier than air. 
This gas will descend to the lower portions of the burrow 
to destroy the animals that breathe it. If one is sure the 
burrow is occupied by a woodchuck, its destruction is com- 
paratively certain. 

OBSERVATIONS FOR PUPILS 
Ground Squirrels or Spermophiles 

I. What kinds of ground squirrels, if any, are found in your locality ? 
Write a short account of what you know about the most abundant 
species. Follow this outline : — 

Size and color. 

Burrowing habits. 

Feeding habits. 

Crops injured. 

Natural enemies. 

Remedies, especially those you have seen tried. 

Prairie Dog and Woodchuck 

1. If either of these animals is common in your locality, write a 
brief account under the headings given above. 

2. Read : — 

American Animals, pages 151-159. The Destruction of Prairie Dogs, U. S. 
Biological Survey, Circular 32. 



CHAPTER XXXI 



The Mice and Rats 



The family of Mice and Rats is known by the technical 
name Muridae. It includes a great number of species, 
many of which are destructive to farm crops. Among the 
well-known members of this group are the muskrats, 
meadow mice, cotton rats, wood rats, white-footed mice, 
and common rats. 

The Short-tailed Field Mice, Meadow Mice or Voles, of 
the genus Microtus, are 
among the most destruc- 
tive of all the rodents. 
Every farmer's boy is 
familiar with the appear- 
ance of these little ani- 
mals. Most boys have 
killed many of them in 
fields or meadows, and have found their rounded nests of 
grasses and other fibers. 

There are about seventy different forms of Meadow 
Mice, but only a few are abundant and widely distrib- 
uted. The one with which most people are familiar is 
called the Common Meadow Mouse, and is known techni- 
cally as Microtus pennsylvanicus. This little creature is 
distributed over most of the United States. The typical 
form is found in the great region east of the Dakotas and 
north of a line running through Tennessee, while five 

312 




Field or Meadow Mouse 



THE MICE AND RATS 



3*3 



slightly different geographical races are scattered over the 
rest of the country. 

As soon as the snow disappears in early spring, it is easy 
to find the winter runways of the Common Meadow Mouse 
in almost any low grassland. They often cover the sur- 
face with an interlacing network that shows how indus- 
triously the mice have been at work beneath the snow. 
Should you follow up these runways carefully, you would 
probably come to shelter nests made of grasses which 
served for temporary quarters through the winter. And 
if you should explore late in spring or in the summer, you 
would often find holes leading to the underground nests in 
which the young are reared. The nests are likely to be 
lined with the soft silk from the milkweed pods or the silky 
seeds of cat-tail flags. 

Meadow mice find their safest home along the borders of 
swamps or other lowlands or in neglected meadows where 
there is a rank growth of grass. The shelter of the grass 
protects them from enemies and enables them to forage 
far and wide. It also serves for warmth in winter and 
furnishes abundant material for nest building. When the 
snow is deep, however, the mice tunnel beneath it in all 
directions, seeking orchards and grain fields where food 
may be found. 

In the matter of food the meadow mice are not very par- 
ticular. They will eat almost any succulent vegetable mate- 
rial. They are especially fond of the swollen roots of the 
wild white morning glory, large numbers of which are often 
stored in underground piles. David E. Lantz once found 
a pile of these thus stored away that weighed more than 
a pound. The roots, stems, leaves, and seeds of most 
vegetable, forage, and grain crops are freely eaten. In 
winter they find the bark of trees and shrubs one of the 



3 X 4 



FARM FRIENDS AND FARM FOES 



chief sources of food, and in consequence they often do 
great damage in orchards, especially those recently set. 
Trees of good size are girdled, while small ones may have 
the bark nearly all torn off the trunk. As this is done in 
winter under shelter of the snow, the owner may not sus- 
pect any damage until it is revealed in spring. 

The Common Meadow Mouse multiplies very rapidly. 
The average is about four litters of young each year with 




WildMorninq-qlory Roots Stored by Meadow Mice 

about six in each litter. It has been estimated that if there 
were no destruction by enemies, " a single pair and their 
progeny in five seasons would amount to nearly 1,000,000 
individuals." This of course does not happen because 
many are killed in various ways, but the estimate shows 
how rapidly these pests multiply under favorable condi- 
tions. It also indicates the necessity of providing as many 
natural checks upon their increase as possible. 

In the great prairie regions of the Middle West the 
Prairie Mouse is abundant and destructive to a great 
variety of crops. It is distinguished from the Common 
Meadow Mouse chiefly by its shorter tail, which is not 
much longer than the hind foot. 

The Prairie Mouse is most likely to develop in neglected 
fields and meadows, from which it scatters into surround- 
ing localities. In range pastures that are not closely 
grazed, these mice are likely to develop in grassy tufts 



THE MICE AND RATS 



315 






neglected by the stock. In orchards that are allowed to 
grow up to weeds and grasses, they are also likely to de- 
velop in such abundance as to injure the trees seriously 
by gnawing the bark. They are often destructive to young 
trees in nurser- 
ies, especially 
where clean cul- 
ture is not given. 

The rate of 
r e production 
of the Prairie 
Mouse is slightly 
less than that of 
the Common 
Meadow Mouse, 
there being 
fewer young in 
each litter. The 
climatic condi- 
tions as to 
drought in sum- 
mer and cold in winter, and the less general presence of 
sheltering materials, also tend to check its increase. But 
it often becomes far too abundant and destructive. 

The runways of the Prairie Mouse and the Common 
Meadow Mouse are generally made above the soil surface, 
though commonly beneath the shelter of overhanging grasses 
or other vegetation. This is an easy way to distinguish 
them from the nearly related Pine Mouse, which makes its 
molelike runways through the soil itself. 

This Pine Mouse in the typical form or that of a closely 
allied geographical race, is distributed over most parts of 
the United States. It makes its home in woodlands rather 




Hyacinth Bulbs eaten by Pine Mice 



316 FARM FRIENDS AND FARM FOES 

than in open fields, but it habitually invades the latter in 
search of food. Its journeys are made just beneath the 
surface of loose soil, in a manner very similar to that of the 
true mole, for which these mice are frequently mistaken. 
They feed upon a great variety of roots, tubers, and bulbs, 
often destroying crops in such a way that the injury is not 
suspected until long afterward. They seem especially fond 
of the tuberous roots of wild violets which are often stored 
up in piles in underground galleries. 

Natural Enemies 

Under natural conditions the rapid development of 
meadow mice is counterbalanced by the fact that they 
furnish a large part of the food of many carnivorous mam- 
mals and raptorial birds. Next to insects, mice are the 
most important item in the food of skunks. They form the 
principal food of weasels and a large part of the food of 
badgers and foxes. 

There is little doubt, however, that the raptorial birds 
are the principal natural enemies of the voles. Hawks and 
owls of many kinds find in these short-tailed mice their 
most important food. This is especially true of the Marsh 
Hawk and the so-called Buzzard Hawks of the genus 
Buteo. The latter include the Red-tailed, Red-shouldered, 
and Broad-winged Hawks. These are a comparatively large 
and heavy species that find field mice an easy prey. The 
Biological Survey found three hundred and fifty of these 
mice among the stomach contents of two hundred and 
twenty-eight Red-tailed Hawks. 

In comparison with their number, the owls seem even 
more useful as mice destroyers than the hawks. These 
birds are abroad at night when the meadow mice are most 



THE MICE AND RATS 317 

active. They are able to fly noiselessly over fields and 
through woods and to gather their prey quickly in their 
hooked talons. Practically all the owls feed largely upon 
field mice, and several of them, notably the Screech Owl 
and the Long-eared Owl, find in them their chief source 
of food. 

It has often happened that in certain regions the natural 
enemies of the voles have been so persecuted as to become 
scarce. When the checks upon their increase are thus re- 
moved, the voles multiply with alarming rapidity and 
become exceedingly destructive. When this occurs, the 
hawks and owls from surrounding regions are attracted 
to the infested locality, where they remain to feast upon 
the mice. These raptorial birds are thus like a standing 
army that nature moves from place to place to subdue in- 
surrections. It is very foolish for man to wage war upon 
this army ; he often has occasion to regret such persecution. 

Various other birds are also useful as destroyers of 
meadow mice. Crows, ravens, and magpies feed upon them, 
especially the young mice. Shrikes destroy great numbers. 
Herons, bitterns, cranes, and gulls also feed upon them. 

Remedial Measures 

The ways in which farmers may aid in keeping meadow 
mice below the danger line are many. One of the most 
effective is by protecting the natural enemies of the voles. 
Another is that of clean culture of the places where the 
mice breed and the tillage of infested fields. Much help 
can also be obtained from cats and dogs that are good 
mousers and from close grazing by the larger domestic 
animals. 

The chief means of direct destruction of the meadow 
mice are traps and poisons. The so-called guillotine traps 



3*8 



FARM FRIENDS AND FARM FOES 



made of coiled wire are useful if placed in the runways, 
either baited or unbaited, but they require constant atten- 
tion. A single hawk left in peace is likely to do the work 
of many traps. Poisons may also be employed, but these 
should be used by persons of mature judgment on account 
of the danger of injury to children, domestic animals, and 
friendly birds. Specific instructions as to the best poisons 
and their use may be obtained from the Biological Survey, 
Washington, D.C In some states the use of poisoned baits 
is prohibited by law. 

The injury done by meadow mice to trunks of trees may 
generally be prevented by protecting the trunk with a 
wrapping of wire screening or some other tree protector. 
In many states wood veneer protectors are used to prevent 
injury by " sun scald " as well as mice. There is much 
evidence, also, to indicate that a simple application of the 
lime-sulphur wash used against the San Jose scale is an 
efficient protection. Tramping down the snow next the 
trees also saves them from injury, but this is not always 
practicable. 

White-footed Mice 

There are many species and varieties of the White- 
footed Mouse., which 
perhaps is the most 
beautiful member of 
the family. They are 
all alike in having the 
lower parts of the 
body as well as the 
legs and feet of a 
white color that con- 
White-footed or Deer Mouse trasts strikingly with 




THE MICE AND RATS 



3 X 9 



the gray above. They live in woods and fields, making 

their nests in logs, hollow trees, sheds, boxes, and almost 

every other available place. 

On the Western plains they 

often nest in the bleaching 

buffalo skulls. They are not 

so distinctly injurious as are 

the meadow mice, though 

they often become locally 

troublesome. 

The Rats 

There is little need to di- 
rect attention to the common 
Brown Rat, doubtless the 
most destructive species of 
rodent in the United States. 
It is so because of its large 
size, its omnivorous feeding 
habits, its rapid multiplica- 
tion, and its ability to penetrate through most obstacles. 
The young mature in six months, and three or four 

litters are born a year, each lit- 
ter consisting of from six to a 
dozen. 

Rats are destructive in fields, gar- 
dens, barns, cellars, storage sheds, 
and houses. They feed on all sorts 
of vegetable and animal products, 
dead or alive. They carry germs 
of diseases, and are altogether 
most pestiferous creatures. War should be waged upon 
them in every practicable way, and buildings should be 




Cornstalk ruined by Brown 
Rats 




Rat Trap used in Burma 




320 FARM FRIENDS AND FARM FOES 

so concreted in cellar and basement as to prevent their 
entrance. 

Many good traps for rats are now available. The so- 
called guillotine trap is perhaps the best. It is on sale 
in various forms in hardware stores. Each trap should 
be thoroughly scalded after use, in order to catch new 
victims. Two ingenious forms of rat traps 
are shown in the accompanying pictures. 
The form used in Burma is a large earth- 
enware vessel closed at the top by a board 
held in place by a heavy stone. The rats 
go in the small hole shown, and are unable 
to get out. Rice or other bait is put in 
the bottom of the jar. The barrel trap is 

Barrel Trap readily understood from the picture : the 
for Rats ..... . . . . . 

bait is fastened in place at b ; a cleat is 

nailed on at a to hold the hinged top from going down on 

that side. 

OBSERVATIONS FOR PUPILS 

Meadow Mice 

i. Observe the runways of these mice, especially in early spring. 
Do you find any holes that go deeper in the ground ? 

2. Look for trees and shrubs in which the bark has been gnawed 
off by meadow mice. Make a list of the kinds of trees and shrubs. 

3. What methods of preventing damage by these pests have you 
known to be tried? 

Read : — 
Meadow Mice in Relation to Agriculture, Yearbook Reprint 388. 

Rats and Mice 

1. How can you distinguish a rat from a mouse? 

2. What damage have you known rats to do? 

3. What ways have you tried to destroy rats? 
Read : — 

How to Destroy Rats, Farmers' Bulletin 369. 






CHAPTER XXXII 
The Rabbits, Pocket Gophers, Moles, and Shrews 

The Rabbits probably rank next to the meadow mice as 
widespread destroyers in field, garden, and orchard. In 
the region east of the Great Plains the familiar Cottontail 
or Gray Rabbit is abundant. In the Northern states the 
Varying Hare or Northern Rabbit is found. In the West 
some form of the large Jack Rabbit occurs, as well as vari- 
ous sorts of Cottontail Rabbits. Consequently, rabbits 
are found over the whole United States, and do injury 
wherever abundant. 

The damage done by Rabbits is due to their voracity and 
abundance. They require large amounts of food and 
multiply rapidly. They eat plant products exclusively, 
including bark, branches, buds, leaves, flowers, fruits, and 
seeds. Wheat, oats, barley, corn, clovers, alfalfa, and other 
grains and grasses are destroyed in the field. Peas, beans, 
cabbage, melons, and other vegetables are destroyed in the 
garden. Bark, twigs, shrubs, and young trees are devoured 
in the orchard and nursery. 

With so varied a food supply, Rabbits naturally prefer 
the more tender and succulent products. Consequently, 
grain, forage, and garden crops, or fallen fruits are most 
commonly eaten, bark, twigs, and other less edible things 
being attacked chiefly in winter or in seasons of drought. 
The chief injury to orchard trees occurs in winter, when 
the bark is stripped off in a characteristic manner. 

In the Western alfalfa fields Rabbits are often very 

321 



322 



FARM FRIENDS AND FARM FOES 



destructive, congregating in large numbers in isolated 
fields and ruining the crop. In the great melon-growing 
regions they often cause the loss of crops by destroying 
young cantaloupe and watermelon plants, and in gardens 
everywhere they are especially destructive to peas and 
cabbage. The greatest damage in orchards is likely to be 
done to comparatively young trees, although in many apple- 
growing regions Rabbits are recognized as a pest always to 
be guarded against. 

The strong hind feet are the only weapons of offense 
with which the rabbits are provided, but their structure, 
habits, and instincts enable them to escape to a large 
extent the attacks of their many enemies. With keen eyes 
so set in the head as to include a large field of vision, with 
large ears to detect the slightest sound, with a coloring 
that makes them almost invisible amid their natural sur- 
roundings, accompanied by an instinct to keep quiet most 
of the time, and with long legs adapted to rapid running, 
rabbits are well equipped in their struggle for life. For- 
tunately for mankind, however, many of their natural 
enemies are able to penetrate their disguises or overtake 
them as they run, so that rabbits furnish food for a consid- 
erable number of mammals and birds. Wolves, foxes, 
wild cats, badgers, weasels, and other carnivorous mammals 
live largely upon rabbits, while practically all the larger 
hawks and owls prey freely upon them. In wild regions 
these various natural enemies serve an important purpose 
in keeping a balance in rabbit life, but in cultivated regions 
such enemies often become so scarce as to be less important. 
As people learn the real value of certain hawks and owls 
as destroyers of rabbits, mice, and other mammals, they 
will probably learn to discriminate between friends and foes 
among birds of prey. 



RABBITS AND POCKET GOPHERS 



3 2 3 



Fortunately, rabbits are good for food, and in most regions 
hunting is the chief means of keeping them in check. In 
localities where jack rabbits are very abundant, many 
people sometimes combine to make a " rabbit drive " in 
which practically all the rabbits for miles around are driven 
into a wire fence inclosure where they are killed by the 
thousand. 

Fortunately, also, rabbits are easily trapped. Most coun- 
try boys have caught them in the figure-four traps. The 
Wellhouse trap 
is an improve- 
ment upon this 
and is readily 
made by follow- 
ing the direc- 
tions at the end 
of this chapter. 
In large or- 
chards two or 

three such traps to each acre of trees will keep the rab- 
bits in check so that little or no damage will be done by 
them. 

Rabbits are also destroyed by poisons, but this method 
should only be used by men who will see that there is no 
possibility of harm to children, domestic animals, or useful 
birds. Injuries to trees are prevented by guards of wire 
screening placed around the trunk. Various washes are 
also helpful in preventing damage to trees. One of the 
best of these is the lime-sulphur wash used to destroy 
the San Jose scale. A liberal spraying or brushing of 
the bark with this late in autumn is a protection for the 
winter. 







^ 


■I 


n 
1 






--*~«"--= ! ' 








Details of Wellhouse Rabbit Trap 



3 2 4 



FARM FRIENDS AND FARM FOES 



Pocket Gophers 



The Pocket Gophers of the family Geomyidae form one 
of the most vexatious groups of rodents. They are rather 
small molelike creatures with a marvelous ability to dig 
their way through loose soil. They live in underground 
burrows and feed upon the roots of trees, vegetables, and 
forage crops, as well as the leaves of many plants. They 
are especially destructive to potatoes and in alfalfa fields. 

The various species of Pocket Gophers found in the 




Georgia Gother 



United States occur chiefly in the region west of the 
Mississippi River, though one is found in Georgia, Alabama, 
and Florida, and another in Wisconsin and Illinois. The 
Prairie Gopher is one of the most destructive species, as it 
inhabits the fertile region of the Mississippi Valley. The 
Plains Pocket Gopher occurs in more arid regions west, and 
the Gray Pocket Gopher is even more widely distributed 
over both prairies and plains. 

The structure of the Pocket Gophers admirably adapts 
them to their underground life. The bodies are thickly 
clothed with fine hair that repels moisture and earth ; the 
heads are pointed, the eyes and ears are small, the front 
feet are especially adapted to digging, and the tail is so 



RABBITS AND POCKET GOPHERS 325 

sensitive that it is used as an organ of touch, when the 
gopher runs backward through the burrows — a habit 
that saves much trouble in turning round. Among the 
most notable points of structure are the remarkable cheek 
pouches that open externally. 

As these gophers make their horizontal burrows, they 
get rid of the soil by making holes to the surface every few 
feet through which the loose earth is pushed out to form a 
little mound. The hole to the mound is finally filled up 
and another made farther along. In meadows and fields 
of forage crops these mounds sometimes make it neces- 
sary to run the mowing machines several inches above the 
surface of the soil, thereby preventing the harvesting of 
much of the crop. This is one of the most troublesome 
effects of the work of gophers. 

The Pocket Gophers work so constantly underground 
that they have comparatively few natural enemies. They 
come to the surface oftener by night than by day, so that 
the owls catch more than the hawks. Other enemies are 
weasels, and bull or gopher snakes. Each of these enter 
the burrows and follow along till they find their victims. 

Fortunately, the Gophers can be rather easily killed by 
the use of poisons without much danger to other animals. 
By punching a hole down to the burrow, with an old spade 
handle having a pointed metallic tip, one can make an 
opening through which small pellets of poisoned food can 
be inserted in the main runways, where there will be little 
danger of their being eaten by other animals. Such pellets 
should net be placed near the mouth of a burrow, because 
of the danger of its being exposed where some other ani- 
mal might get it. Strychnine is the poison most commonly 
used, and the prepared poison pellets are on sale in many 
drug stores. Great care is, of course, necessary in han- 



326 FARM FRIENDS AND FARM FOES 

dling this deadly poison ; special pains should always be 
taken that none of the poisoned materials be left within 
the reach of children. 

These pests may be caught in traps placed in the burrows. 
Various forms of traps for this purpose are now upon the 
market. Gophers may also be killed by the use of carbon 
bisulphide, a volatile liquid that rapidly vaporizes when 
placed in the burrow. The vapor is a deadly poison and 
soon kills any animal that breathes it. It is also inflam- 
mable, and no fire must be brought near it. 

Moles and Shrews 

There is a small order of mammals called the Insectivora 
or Insect-eaters. It includes the Moles and Shrews. These 
animals live mostly in underground burrows and are 
seldom seen except when turned over by accident. The 
burrows of Moles are familiar to many people, though 
doubtless the burrows of Pine Mice are often mistaken for 
them. Moles feed largely upon earthworms and under- 
ground insects, but are also often troublesome when they 
make their runways through lawns and gardens. 

In the great order Carnivora or Flesh-eaters are found 
many of the large wild mammals, such as bears, wolves, 
coyotes, foxes, and badgers, as well as a number of smaller 
ones, such as weasels and ferrets. Many of these are 
efficient checks upon destructive rodents, but there is 
comparatively little help to be expected from them in 
thickly settled regions. 

Making the Wellhouse Trap 

The following directions for making this excellent rabbit 
trap are given by David E. Lantz : — 



RABBITS AND POCKET GOPHERS 



3 2 7 



" The trap is a box made of 6-inch fencing boards, old 
ones being preferred. The box is about 21 inches long, 
closed at the back by a board, but in front by a wire door 
only. The door is hung from the top and swings inward. 
A cleat at the bottom prevents its opening outward. The 
trap is set and the wire door is kept open by a wire trigger 
rod, held in place by two staples fastened to the top of the 
box. This trigger is bent downward near the rear of the 
trap and formed into a loop or a figure eight. As the rab- 
bit enters the trap and crowds into the back part, it pushes 
upon the loop, moves the trigger wire backward, and releases 
the wire door. This falls and makes the rabbit a prisoner. 
Bait may be used, but is not necessary, since the cottontail 
is constantly looking for dark places to hide from enemies 
or cold winds. Mr. Wellhouse uses about three traps per 
acre in young orchards and many among the bearing trees. 
They are regularly looked after by boys, and so effective 
have they proved that no serious losses from rabbits have 
occurred in his orchards. 

" The materials needed for making a Wellhouse trap are : 
Four boards 1 by 6, 21 inches long; one piece 1 by 6, 8 
inches long for the back ; a short cleat for the door stop ; 
28^- inches of wire to serve for the door ; 22 inches of wire 
for the trigger ; four small staples for hanging the door 
and trigger ; and nails." 



OBSERVATIONS FOR PUPILS 

1 . Write or tell a story with this title : What I know about Rabbits. 
.2. Read-: — 

The Rabbit as a Farm and Orchard Pest, Yearbook Reprint 452; The Story of 
Raggylug in Wild Animals I have Known. 



BIBLIOGRAPHY 

Teachers or pupils may obtain the various Farmers 1 Bulletins and 
other publications of the United States Department of Agriculture 
referred to in connection with the Observations for Pupils free of charge 
on application to the Secretary of Agriculture. Each school should have 
a set of the recent issues of the Yearbook of the Department and of the 
Yearbook Reprints referred to in these pages. 

A set of the bulletins of the State Experiment Station should also be 
on file for reference, with extra copies of such as are especially useful in 
connection with the subjects studied. 

The following books are referred to in connection with reading for 
pupils. They may be purchased through any book dealer. 

Insects 

Dickerson : Moths and Butterflies. 

Howard : The Insect Book. 

Kellogg : American Insects. 

Murtfeldt and Weed : Stories of Insect Life. 

Peckham : The Solitary Wasps. 

Weed : Life Histories of American Insects. 

Weed : Nature Biographies. 

Fungi 
Duggar : Fungous Diseases of Plants. 

Birds and Mammals 

Eckstorm : The Bird Book. 
Forbush : Useful Birds and their Protectio7i. 
Seton : Wild Animals I have Known. 
Stone and Cram : American Animals. 
Weed and Dearborn : Birds in their Relations to Man. 

328 



INDEX 



Acridiidae, 67. 
Aleyrodes, 273. 
Ambush bugs, 167. 
Andrenidse, 203. 
Anthracnose, bean, 255. 

cotton, 256. 

raspberry, 256. 
Ants, 169, 173. 

and aphides, 92. 
Aphides, 87, 95, 187. 
Aphidius, 179. 
Aphis, apple, 91. 

corn-root, 92. 

cotton, 90. 

dock, 91. 

European grain, 89. 

melon, 91. 

orange, 91. 

spring-grain, 87. 
Aphis lions, 171. 
Apidae, 203. 
Apina, 203. 
Apple blossom, 195, 210. 

bitter rot, 246. 

maggot, 125. 

scab, 245. 

of Peru, 41. 
Army worm, 107, 188. 
Ascomycetes, 242. 
Ascospore fungi, 242. 
Asilidae, 166. 
Aspen, 25. 
Assassin bugs, 168. 
Asters, wild, 20, 23. 

Bacillus amylivorus, 259. 
Bacteria, nitrifying, 275. 

nitrogen-gathering, 276. 

symbiotic, 278. 



Bacterial diseases, 259, 273. 
Bacteriosis, bean, 263. 

melon, 263. 
Bark lice, 82, 95. 
Barley, mouse, 15. 

wild, 15. 
Barnyard grass, t,t,. 
Bean blight, 263. 
Bees, 203. 
Beetle, asparagus, 136. 

Colorado potato, 135. 

cucumber, 137. 

May, 131, 147. 
Beetles, 131. 

click, 134. 

flea, 139. 

ground, 164. 

ladybird, 165. 

Lamellicorn, 132. 

leaf, 135. 

long-horn, 140. 

predaceous, 164. 

snapping, 134. 

tiger, 164. 
Beggar ticks, 19. 
Bermuda grass, 61. 
Billbugs, 143. 
Bindweed, black, 42. 

hedge, 41. 
Birch, gray, 25. 
Bird's-eye rot, 256. 
Bitter rot, 246. 
Blackbird, Brewer, 300. 

crow, 300. 

redwinged, 300. 
Black knot, 242, 257. 
Black rot, 251. 
Blattidac, 70. 
Bluebird, 298. 



329 



33° 



INDEX 



Blue-grass, flat-stemmed, 14. 
Bobolink, 293. 
Bollworm, 111. 
Bombycine moths, 102, 120. 
Borer, apple-tree, 140. 

locust, 140. 
Bottle-grass, 32. 
Bouncing Bet, 10. 
Bracken, 24. 
Brake fern, 24. 
Brown rot, 247. 
Buckwheat, wild, 42. 
Buffalo bur, 39. 
Bumblebees, 204. 
Burdock, 7. 
Bur marigold, 19. 
Butter-and-eggs, 10, 11. 
Buttercups, 24. 
Butterflies, 97, 119. 
Butterfly, Asterias, 97. 

black swallowtail, 97. 

cresphontes, 98. 

mourning cloak, 98. 

Cabbage butterfly, 97, 186. 

clubroot, 257. 

maggot, 127. 

rot, 261. 

worm, 97, 186. 
Carabidae, 164. 
Caraway, n. 
Carnivora, 320. 
Carrot, small, 21. 

wild, 20. 
Catbird, 299. 
Caterpillar fungi, 272. 
Cecidomyiidas, 123. 
Cedar, red, 25. 
Cerambycidae, 140. 
Chalcid flies, 152, 182. 
Charlock, 33, 47. 
Cheat grass, 45. 
Cherry, black, 28. 

choke, 28. 

flower, 194. 
Chess, 45. 



Chickweed, mouse-ear, 34. 

smooth, 34. 
Chicory, n. 
Chinch bug, 75. 

fungus, 76. 
Chondrilla, 19. 
Chrospidae, 171. 
Chrysomelidae, 135. 
Cicada, dog-day, 78. 

periodical, 78. 
Cicadidae, 77. 
Cicindelidae, 164. 
Cinquefoil, common, 23. 

Norwegian, 23. 

silvery, 23. 
Clotbur, 38. 
Clover-seed midge, 124. 
Clubroot, cabbage, 257. 
Coccidae, 82. 
Cockle, 49. 
Cocklebur, 38. 
Cockroaches, 70. 
Codling moth, 113. 
Coleoptera, 131. 
Cone-flower, 19. 
Corn cockle, 49. 

rootworm, northern, 137. 
southern, 138. 

rust, 238. 

smut, 228, 230. 

stalk-borer, 112. 

worm, in. 
Cotton boll weevil, 144, 148. 

rot, 203. 

wilt, 251. 
Couch-grass, 14. 
Cowbane, spotted, 27. 
Crab-grass, ^^. 
Crane flies, 125. 
Crazy weed, 26. 
Cricket, black, 69. 

mole, 70. 

tree, 70. 
Cross-fertilized flowers, 199. 
Crow, 293. 
Crown gall, 261. 



INDEX 



33 1 



Currant worm, 150, 153. 
Cutworms, 109. 
Cynipidae, 152. 
Cypress spurge, 10. 

Daisy, oxeye, 16. 
Dandelion, 3. 
Day lily, 10. 
Diptera, 122, 188, 207. 
Dock, bitter, 8. 

broad-leaved, 8, 59. 

curled, 8. 

sour, 8. 

yellow, 8. 
Dodder, 53. 
Dragon flies, 170. 

Elaters, 134. 
Elecampane, 10. 
Entomophthoreae, 271. 
Evening primrose, 9. 

False flax, 49. 
Fern, brake, 24. 

cinnamon, 24. 

flowering, 24. 

interrupted, 24. 

sensitive, 24. 
Fertilization of flowers, 194. 
Finger-grass, 33. 
Fireweed, 9. 
Five-fingers, 23. 
Flea-banes, 19. 
Flea beetles, 139. 
Flies, two-winged, 122, 188, 207. 
Fly-away-grass, 32. 
Foxtail, green, 32. 

yellow, 32. 
Fruit maggots, 125. 
Fungicides, 267. 

Gallflies, 152. 
Gallfly, blackberry, 152. 
Gall gnats, 123. 
Gill-over-the-ground, 44. 
Goldenrods, 23, 61. 
Goosefoot, 35. 



Gophers, 307. 

Georgia, 324. 

pocket, 324. 
Grackle, bronzed, 300. 

purple, 300. 
Grape mildew, 223. 
Grape rot, black, 251. 
brown 223. 
Grape slug, 151. 
Grasshopper, meadow, 69, 72. 

structure of, 65. 
Ground cherries, 40. 
Ground squirrels, 307, 312. 
Gryllidae, 69. 
Gypsy moth, 103. 

Hardhack, 13, 25, 62. 
Harlequin cabbage bug, 77, 94. 
Harvest fly, 78. 
Hawk, marsh, 302. 

moths, 101, 208. 

sparrow, 202. 
Hawkweed, orange, 17. 
Hemiptera, 73. 
Hessian fly, 123, 129. 
Honeybees, 206. 
Horse nettle, 39. 
Horse-radish, n. 
Horseweed, 37. 
Husk tomato, 40. 
Hymenoptera, 149, 169. 
Hyperparasites, 180. 

Ichneumon flies, 174. 
Insecticides, 155. 
Insectivora, 326. 
Insect-killing fungi, 271. 
Ironweed, 20. 

Jamestown lily, 41. 

weed, 41. 
Jimson weed, 41. 
Joe-pye weed, 20. 
Johnson-grass, 14, 61. 
Jumping plant lice, 82. 
Juniper, low, 25. 



332 



INDEX 



Kingbird, 301. 

Lacewinged flies, 171. 
Ladybird, Australian, 166. 
Lamb-kill, 28. 
Lamb's-quarters, 35, 43. 
Larkspur, dwarf, 27. 

purple, 27. 

Wyoming, 27. 
Laurel, mountain, 28. 

sheep, 28. 
Leaf hoppers, 78, 94. 

apple-tree, 81. 

grape, 80. 

rose, 81. 
Leaf miners, 115, 129, 130. 

rollers, 115. 
Leaf roller, rose, 115. 
Lemon rot, 224. 
Lepidoptera, 96, 207. 
Lettuce, prickly, 6. 
Lima bean mildew, 223. 
Live-forever, 10. 
Loco weed, stemless, 26. 

woolly, 26. 
Locust, black, 25. 

honey, 25. 

yellow, 25. 
Locustidae, 69. 
Locusts, long-horned, 69. 

short-horned, 67. 

Mad apple, 41. 
Mantids, 71, 171. 
Marmots, 310. 
Meadow lark, 292. 
Mice, field, 312. 

meadow, 312, 320. 

pine, 315. 

prairie, 314. 

white-footed, 318. 
Microgaster flies, 177. 
Microtus pennsylvanicus, 312. 
Mildew, bean, 254. 

cherry, 254. 

gooseberry, 254. 



Mildew, grape, 223, 254. 

Lima bean, 222. 

melon, 223. 

onion, 223. 
Mildews, downy, 219. 

powdery, 252, 258. 
Milkweed, 23. 
Molds, 215. 

Morning glory, wild, 41. 
Moth, brown-tail, 106, 121. 

Cecropia, 102. 

Luna, 102. 

Polyphemus, 102. 

Promethea, 103. 
Muridae, 312. 
Mushrooms, 215, 224. 
Mustard, black, ^3, 48. 

English, 47. 

hedge, 48. 

tall, 48. 

tumbling, 48. 

wild, S3, 47- 

Noctuida? ; 107. 

Oak twig primer, 141. 
Oats, wild, 4, 7. 

smut, 226, 229. 
Old-witch-grass, 32. 
Onion maggot, 128. 

mildew, 223. 

smut, 229. 
Orange-dog caterpillars, 98. 

fruit fly, 124. 

maggot, 126. 
Orthoptera, 65. 
Owlet moths, 107. 

Papilionina, 97. 
Parasite, plant-louse, 178. 

primary, 180. 

secondary, 180. 

tertiary, 180. 
Parasitic fungi, 218. 
Peach, leaf curl, 243. 

twig borer, 116. 



INDEX 



333 



Peach, worm, 116. 
Pear blight, 259, 263. 

leaf blight, 249. 

midge, 124. 

scab, 245. 
Pelecinus fly, 185. 
Pentatomidae, 166. 
Peppergrass, 33. 
Phcebe, 301. 
Phycomycetes, 219. 
Phymatidae, 167. 
Physalis, 40. 
Pigeon-grass, 32. 
Pigweed, common, 36. 

white, 35, 43. 
Pine sawyer, 141. 
Plantain, broad-leaved, 8. 

large-bracted, 21. 

narrow-leaved, 8, 22. 

western, 21. 
Plum, curculio, 141, 146. 

pockets, 244. 

pollination of, 200. 
Pocket gophers, 324. 
Poison hemlock, 27. 

ivy, 27. 
Pollination of flowers, 194. 
Poppy, corn, 50. 

field, 50. 
Potato blight, early, 255. 
late, 219. 

scab, 254. 
Prairie dog, 310. 
Predaceous, beetles, 164, 172. 

bugs, 167, 172. 

flies, 168, 172. 

insects, 163. 
Proctotrypid flies, 185. 
Psyllidae, 82. 
Puccinia coronata, 238. 

pruni, 239. 

rubigo-vera, 237. 

Sorghi, 238. 
Purslane, 35, 43. 

Quack-grass, 14, 31, 61. 



Rabbit, cottontail, 321. 

jack, 321. 

northern, 321. 
Radish, maggot, 127. 

wild, 33. 
Ragweed, ^y. 

giant, 37. 
Railroad worm, 125. 
Rat, brown, 319. 
Rattlebox, 27. 
Rattleweed, 27. 
Redroot, 36. 
Reduviidae, 168. 
Rib-grass, 22. 
Ribwort, 22. 
Robber flies, 168. 
Robin, 294, 298. 
Roman wormwood, 37. 
Root maggots, 126, 130. 
Rose, bug, 133. 

chafer, 133, 148. 
Rust, apple, 238. 

asparagus, 231. 

cedar, 238. 

clover, 234. 

corn, 238. 

hollyhock, 240. 

oats, 238. 

plum, 239. 

raspberry, 239. 

rose, 235. 

wheat stem, 235. 
leaf, 237. 
Rusts, 231, 240. 

St. Johnsworts, 23. 
Salsify, 11. 
Sassafras, 25. 
Savin, 25. 
Sawflies, 149. 
Sawfly, willow, 150. 
Scale, black, 85. 

cottony maple, 83. 

insects, 82. 

San Jose, 86. 
Seventeen-year locust, 78. 



334 



INDEX 



Sheep sorrel, 22. 
Shepherd's purse, 34. 
Smut fungi, 226. 
Sneezeweed, 27. 
Soapwort, 10. 
Soldier bugs, 167. 
Sorrel, field, 22. 

sheep, 22. 
Sparrow, chipping, 296. 

English, 297. 
Sparrows, 293, 296. 
Spanish needles, 19. 
Sphingidae, 100. 
Sphinx moths, 100, 119, 208. 

Pandorus, 101. 
Squash, blossoms, 196, 211. 

bug, 73, 94. 
Squirrel-tail grass, 15. 
Stick-tights, 19. 
Strawberry, barren, 23. 

blossoms, 198, 211. 

leaf spot, 250. 

wild, 23. 
Sumach, dwarf, 29. 

mountain, 29. 

poison, 29. 

smooth, 29. 

staghorn, 29. 

velvet, 29. 
Sundrops, 10. 
Sunflower, wild, 19. 
Superparasitism, 181. 
Sweet clover, 11. 

fern, 13, 25. 
Syrphidae, 169. 
Syrphus flies, 169. 

Tachina flies, 188. 
Tachina fly, large-horned, 190. 
Tachinidae, 188. 
Tansy, n. 
Teasel, 10. 

Tent caterpillars, 103, 186. 
Tenth red inidas, 149. 
Thistle, Canada, 18. 
pasture, 17. 



Thistle, Russian, 150. 

Thorn apple, 41. 

Tickle-grass, 15. 

Tineina, 116. 

Tipulidae, 126. 

Toadflax, n. 

Toadstools, 215. 

Tomato worms, 101. 

Tomato, strawberry, 40. 

Tomato fruit worm, in. 

Tortricina, 115. 

Tree hoppers, 79. 

Trumpet miner, apple-leaf, 116. 

Tumblewecd, 36. 

Russian, 50. 
Turnip maggot, 127. 

Uredinales, 231. 
Ustiliginales, 226. 

Varying hare, 321. 
Vegetable oyster, 1 1 . 
Verbena, wild, 20. 
Vervain, 20. 
Vespidae, 170. 
Voles, 312. 

Walking sticks, 71, 72. 
Wasps, social, 170. 

solitary, 170. 
Webworm, fall, 105, 186. 
Wheat jointworm, 153. 

midge, 124. 
Wheel bug, 168. 
White fly fungi, 273. 
White grub, 131. 
White-tops, 19. 
Whiteweed, 16. 
Willow-herb, 9. 

Wire-grass, 14. 
Wireworms, 134. 
Witch-grass, 14, 31. 
Woodchuck, 310. 

Yarrow, n. 



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